Below is an article on how we sign ourselves with the Cross, courtesy of Orthodoxwiki (here), its evolution from early Church history to today:
The first mention of Christians making the sign of the Cross is in the 2nd Century by Tertullian who said: “In all our travels and movements, in all our coming in and going out, in putting of our shoes, at the bath, at the table, in lighting our candles, in lying down, in sitting down, whatever employment occupieth us, we mark our foreheads with the sign of the cross” (De cor. Mil., iii).
In the early Church it is believed that the cross was made only on the forehead. Therefore Tertullian also says: “We Christians wear out our foreheads with the sign of the cross.” It is also believed that Christians would also use one finger to make the sign of the cross on their foreheads or on other items. Therefore in the life of St. Barbara, we read: “One day, as Barbara stood by the pool facing the east she said, In the name of the Father, the Son and the Holy Spirit, and she miraculously drew the sign of the cross in the marble wall of the bathhouse with her finger.”
That the cross was made with only one finger is also confirmed by St. Epiphanius in his Panarion (Adv. Haer. Xxx, 12), where he speaks of a certain Josephus, who imparted to a vessel of water the power of overthrowing magical incantations by “making over the vessel with his finger the seal of the cross” pronouncing the while a form of prayer. Again half a century later Sozomen, the church historian (VII, xxvi), describes how Bishop Donatus when attacked by a demon “made the sign of the cross with his finger in the air and spat upon the monster”.
However, by the fourth century it appears as more than one finger began to be used for making the sign of the cross. Thus St Cyril of Jerusalem, in his Catecheses (xiii, 36) remarks: “Let us then not be ashamed to confess the Crucified. Be the cross our seal, made with boldness by our fingers on our brow and in every thing; over the bread we eat and the cups we drink, in our comings and in goings; before our sleep, when we lie down and when we awake; when we are traveling, and when we are at rest.”
It is believed that two fingers began to be used to make the sign of the cross, as a guard against Monophysitism. Thus by using two fingers, one would profess the two natures in Christ. It is therefore not surprising that the first evidence of using two fingers to make the sign of the cross is found in the writings of Theodoret of Cyrus, who is well known for his antagonism towards the Monophysites. Thus Theodoret of Cyrus writes: “Thus does one bless with the hand and cross oneself: Holding three fingers together evenly the thumb and the last two fingers-confesses a mystery in the image of the Trinity: God the Father, God the Son, and God the Holy Spirit. There are not three gods, but one God in Trinity; there is a distinction of names, but one Godhead. The Father is unbegotton; the Son is begotten of the Father, yet not created; the Holy Spirit is nither begotten nor created, but proceeds. They are three in one Godhead; but one in power, one in honour, one in the adoration of all creation, angles and men. Such is the explanation of these three fingers. Joining two fingers together-the index and the middle finger-and extending them, with the middle finger slightly bent, represents the two natures of Christ: His Divinity and His Humanity. He is God according to His divinity and Man according to His hummanity, perfect in both natures. The index finger represents His divinity, while the middle finger repersents His hummanity, since He came down from on high and saved those below. The bending of the middle finger is interperted to mean that He bowed the heavens and came down upon the earth for our salvation.” (Domostroi Excerpt, chap. 13, Carolyn Johnston Pouncy, Cornell University, 1994)
Saint Peter Damascene (+ 775 A.D.) also confirms this in his following discourse in the Philocalia: “The holy Fathers have handed down to us the meaning of this holy sign, in order to refute heretics and unbelievers. The two fingers and the one hand then, represent then the crucified Lord Jesus Christ, who we profess as having two natures in one person. The right hand recalls His unlimited might and His sitting at the right hand of the Father. And one begins to trace it from above because of His decent from the heavens to us on earth. Furthermore, the movement of the hand from the right side to the left drives away the enemies and indicates that the Lord through His invincible might has conquered the devil who is on the left, powerless and gloomy being.” (Philocalia page 642)
It is also claimed that St. Meletius the Confessor, Bishop of Antioch, also wrote a treaties outlining the signing of the cross with two fingers. Nevertheless, it must be admitted that St. Meletius the Confessor, as well as St. Cyril of Jerusalem, Theodoret of Cyrus and St. Peter of Damascus all belonged to the local Church of Antioch, which at various points in time included all of Middle East as well as sometimes including Cappadocia, Asia Minor, Palestine, Sinai and elsewhere, prior to the establishment of the Patriarchates of Constantinople and Jerusalem. Therefore, it is possible that the signing of the cross with two fingers was not a universal custom, but only an Antiochian tradition. This would also make much sense, because the Antiochians were staunch defenders of Orthodoxy against Monophysitism, and thus, hence the emphasis of two natures and the signing of the cross with two fingers.
Nevertheless, by the time the Russian lands were enlightened in the 10th century, it was this tradition that prevailed in Cappadocia, Asia Minor, and wherever else missionaries would have been sent to Russia from Byzantium. Hence, the Russian Church received this ancient tradition right from the very beginning, and preserved it for several centuries afterwards.
However, at least by the 9th century, the practice had become prevalent throughout the Orthodox East and West for the sign of the cross to be made using three fingers instead of two. The thumb, index finger and middle finger were joined together to symbolize the Holy Trinity, while the ring finger and little finger were tucked into the palm to represent the two natures of Christ.
The first written record of this form is found in the writings of the Orthodox Pope Leo IV of Rome who reposed in 855 A.D., and whom St. Photius the Great considered a Saint and attributed many miracles. Thus, Pope Leo writes: “Sign the chalice and the host, with a right cross and not with circles or with a varying of the fingers, but with two fingers stretched out and the thumb hidden within them, by which the Trinity is symbolized. Take heed to make this sign rightly, for otherwise you can bless nothing” (see Georgi, “Liturg. Rom. Pont.”, III, 37).
In about 1000 A.D., Aelfric, Abbot of Eynsham in England, who reposed in 1020 A.D., wrote the following: “A man may wave about wonderfully with his hands without creating any blessing unless he make the sign of the cross. But if he do the fiend will soon be frightened on account of the victorious token. With three fingers one must bless himself for the Holy Trinity” (Thorpe, “The Homilies of the Anglo-Saxon Church” I, 462).
Over a century after the schism of 1054, the Frankish Pope Innocent III (1198-1216), made the following declaration: “The sign of the cross is made with three fingers, because the signing is done together with the invocation of the Trinity. … This is how it is done: from above to below, and from the right to the left, because Christ descended from the heavens to the earth, and from the Jews (right) He passed to the Gentiles (left).”
The practice of making the sign of the cross with three fingers may or may not have originated in the West. Nevertheless, it existed in the West by at least the year 855, before the repose of the Orthodox Pope Leo IV, and thus was practiced in the Orthodox West before the schism of 1054, and even for several centuries after the schism. In the East, the practice of making the sign of the cross with three fingers was the common practice by at least the 12th century. Thus the Greek Church, the Serbs, Bulgarians, Albanians, Georgians, Wallachians, Moldavians and even the Russians living under Polish rule all adopted the signing of the cross using three fingers representing the Holy Trinity. Interestingly, the use of three fingers also became the norm among the Monophysites Copts, Syrians, Armenians, and even the far off Ethiopians. However, all of the Monophysites make the sign of the cross from right to left, contrary to the practice of the Orthodox. The Nestorians of Mesopotamia, Persia and India also use three fingers today. This is ironic because the Nestorians would want to emphasize the two natures of Christ. Yet they do not sign the cross with two fingers representing the two natures, but rather with three fingers representing the Holy Trinity. The Nestorians also sign the cross from right to left, thereby having the exact same practice as the Greeks.
Thus, the practice of making the sign with three fingers had reached the Italians, Spaniards, French, Germans, and English in the west. It had reached the Greeks, Bulgarians, Georgians, Albanians, Serbs, Wallachians, Moldavians and Poles. It had also reached the Egyptians, Syrians, Armenians, Mesopotamians, Persians, and even the far off Ethiopians and Indians. But it had not reached the Russians!
The Orthodox Church of Russia continued to observe the practice of making the sign of the cross with two fingers, as had been prescribed by Theodoret of Cyrus and St. Peter of Damascus. The writings of these Fathers were even inscribed in the typicon (trebnik) used by the Russian Church. When by the middle of the 16th century, the Russians had realized their practice differed from the Poles to the west, and the Bulgarians, Greeks and Georgians to the south, measures were taken to decide which practice was more original. These issues were addressed at the Council Convened by Emperor Ivan the Terrible in the year 1551. This Council is also called the Stoglav Council, or the “Council of the One Hundred Chapters.” However, this Council did not merely decide that the sign of the Cross should be made with two fingers, but it also condemned anyone who did not perform the sign of the Cross in this manner!
Canon 31 of the Stoglav Council reads as follows: “The sign of the cross must be made according to the rules, in the form of a cross; and the right hand, that is, the dextral hand, must be used in crossing oneself, with the thumb and the two lower fingers joined together, and the extended index finger joined to the middle finger, slightly bent; thus should prelates [and] priests give their blessing and thus should men cross themselves… It befits all Orthodox Christians to hold their hand thus, and to make the sign of the cross upon their face with two fingers, and to bow, as we said before. If anyone should fail to give his blessing with two fingers, as Christ did, or should fail to make the sign of the cross with two fingers, may he be accursed…”
In 1569, the Frankish Pope abolished the use of three fingers in the West, and ordered the sign of the cross to be made with five fingers, and from right to left, instead of left to right. However, this practice was not introduced in the East, neither among the Orthodox, nor among the Monophysites and Nestorians.
In 1589, Ecumenical Patriarch Jeremias II Tranus visited Russia and elevated the Metropolitan of Moscow to the rank of Patriarch. The Greek and Russian Churches thus maintained their unity without fail, despite the fact that the Greeks made the sign of the cross with three fingers, while the Russians made it with two.
In 1654, Patriarch Nicon of Moscow, after having visited the Ottoman Empire, understood that the practice of the Russian Church differed from that of the Greeks, Georgians, Romanians, Bulgarians and Serbs. He therefore called a Council, with the Czar’s approval, in which he requested revisions to be made to liturgical texts, as well as for the Russian Church to adopt the practice of using three fingers to make the sign of the cross. However, this immediately led to sharp opposition. The most prominent enemy of reform was the well-known Protopresbyter Abbacum.
In 1666-1667, the Russian Church called another Council, in which it invited representatives from the Churches of Alexandria, Antioch, Jerusalem, Constantinople and elsewhere. However, none of the guests were Patriarchs, and some of the bishops had already been deposed by their own Churches. Furthermore, it is believed that many of the bishops were paid by the Russian State, with money and products, to vote in favor of the reform. The following is an account by Protopresbyter Abbacum regarding his dialogue with the Greek and Russian bishops at the Council of 1666-1667:
“The last word they said to me was, “Why are you stubborn? All of Palestine – and the Serbs, the Albanians, the Wallachians, the Romans and the Poles – all of them cross themselves with the three fingers and only you remain obstinate and make the sign with two fingers. That is not fitting!” And I answered them for Christ as follows: “Ecumenical teachers! Rome has long since fallen and lies prostrate, and the Poles perished with them, and are the enemies of Christians to the end. Among you Orthodoxy has become mottled because of the violence of Mehmet the Turk – and one must not be amazed at you: you have become powerless. And so henceforth, come to us to study, for, by the grace of God, we have autocracy. Before Nikon the apostate, in Russia, under our pious princes and tsars, Orthodoxy was complete, pure and undefiled and the church without uproar. Nikon, that wolf, and the Devil ordered us to cross ourselves with three fingers: but our first pastors crossed themselves with two fingers and likewise gave their blessing with two fingers according to the tradition of the holy fathers, Meletius of Antioch, the blessed Theodoret Bishop of Cyrene, Peter of Damascus, and Maximus the Greek. Likewise the local council of Moscow under Tsar Ivan ordered us to cross ourselves and give the blessing, putting our fingers together in that way, to make the sign of the Cross and give the blessing, as of old the Holy Fathers Meletius and others taught. Then in the time of Ivan the Tsar, there were the standard-bearers, Gurias and Barsanuphius, wonder-workers of Kazan, and Philip the Abbot of Solovki among the Russian Saints.” (‘Gudzy, Zhitie’ p. 101.)
The Council of 1666-1667, nevertheless, reversed several decisions of the Stoglav Council held under Ivan the Terrible over a century earlier in 1551. Thus the use of three fingers to make the sign of the cross was no longer anathematized. On the contrary, the Synod of 1666-1667 anathematized all those who continue to make the sign of the cross with two fingers. Protopresbyter Abbacum was among those anathematized. He was imprisoned for another decade, after which he was burnt alive by order of the State.
Finally, in the Sacred Rudder, St. Nicodemus of Mt Athos informs us in his 2nd footnote to the 91st Canon of St Basil the Great (Rudder, page 645 in the Greek edition, and page 857 in the English version): “The ancient Christians used to make the sign of the Cross with a different configuration of the hand, that is to say, more explicitly speaking, with only the two fingers of the hand, namely, the index finger and the middle finger, as St. Peter Damascene informs us (page 642 of Philocalia), where he says that the hand as a whole signifies the single substance of Christ, while the two fingers signify His two natures. But the custom now prevailing among Christians is for the two fingers to be conjoined with the thumb; and with these three together to represent the Holy Trinity…” (OCES, The Rudder, “The 92 Canons of St Basil the Great,” Canon 91, footnote 2)
The most ancient of Orthodox icons prove that at least the blessing was performed using the two finger gesture of the hand, as is still the practice among Old Believer hierarchs and priests to bless the flock, and as all Old Believers make the sign of the cross upon themselves.