From Liturgy of Pentecost of the Syriac Churches - Catholic and Orthodox - of which Islam was a heresy that sprang up in the 600s:
Glory be to Him who is invisible, mysterious and beyond human thoughts, mind and comprehension. He, who is self existent, self sufficient, maker and author of all things visible and invisible and has no beginning and will continue without end; the eternal, everlasting and the incomprehensible one true God, one nature, one authority and one will of the Father, the Son and the Holy Spirit. There is not in Him a name without a person and no person is younger or older than the other person, neither is there any transformation or alteration of one person is another in greatness and smallness.
No name or person is younger or separated from the divine substance. Whenever the Father is mentioned, the Son and the Spirit are of Him, and whenever the Son is mentioned, the Father and the Spirit are acknowledged in Him, and whenever the Spirit is mentioned the Father and the Son are included.
The Father begets and is not begotten. The Son is begotten and does not beget. The Holy Spirit proceeds from the Father and takes from the Son and is consubstantial and co-essential with the Father. To Him be glory, honor and dominion at this time of the celebration of Pentecost and at all festivals, times, hours, seasons and through all the days of our life forever.
Amen.
O God, invisible, inscrutable, eternal and immeasurable, You are conceivable in the oneness of essence and are apparent in three Holy persons, who are understood in three characteristic attributes by all rational beings and are acknowledged one God in three worshipped persons; a perfect Trinity of three perfect persons; Father, Son and Holy Spirit; one sublime essence, one eternal nature, one true God.
O God the Father, You were pleased to restore man who was created in Your own image, and who by his free will slid into idolatry; You sent Your Word and Your Son for our reformation.
When He became man without any alteration, He explained to us the ineffability of the Godhead, and announced to us the unknown things and the hidden secrets of Your wisdom in that he knows You and in that he is of You.
He informed us about the third light of the Godhead who is the person of the Holy Spirit, who proceeds from You, O Father, in an indescribable manner. The Spirit of truth, the Spirit of wisdom, the Spirit of might, the Spirit of knowledge, the perfecter Spirit, the performer Spirit, the non-quantiative Spirit, the affectionate Spirit, the Spirit that guides the teachers; the beneficent Spirit, the powerful Spirit, the almighty Spirit, the Spirit that is simple in His nature and manifold in His operation, who is the source of divine gifts and is consubstantial with You and with Your only begotten Son, the Spirit who spoke in the
law through the prophets and the disciples, who is near to all and fills all, who effects sanctification with authority, and not entreatingly, upon those with whom He is pleased.
Through Him we beseech You on this glorious feast of Pentecost, on which the Holy Spirit descended upon the holy apostles, that He may also descend upon us, Your servants
and worshippers, so You may fill us with his holy gifts; uproot from us all the defilement of sin, raise us up as pure temples and presentable habitations for Your dwelling and make us not submissive to the turbulence of the enemies and bring a good remembrance and a joyful repose to all the faithful departed, the children of the Holy Church, especially our parents, teachers and brethren, who lived their life in the true faith.
For You reign over us, O God, the Father and Lord of all, with Your only begotten Son, who quickens all, and Your Holy Spirit the most blessed, worshipped, life-giving and consubstantial with You, now and forever.
