As it is plainly denied by clerics on your side that θεοτοκος means the same as “Mother of God,” versus “Birth-giver to God” or “God bearer,” with the latter more denoting instrumentality than what "Mother" normally ontologically conveys, the then what is a "good translation' is based upon theological preference, which was my point, versus a quote by a native Greek speaker providing the most accurate translation.
It is sobering to realize what is happening now to the Christians who have chanted this hymn
Sad indeed (coming here incrementally) but I hope they all are Christians most of all.
"Ὁ Μονογενὴς Υἱὸς καὶ Λόγος τοῦ Θεοῦ, ἀθάνατος ὑπάρχων καὶ καταδεξάμενος διὰ τὴν ἡμετέραν σωτηρίαν σαρκωθῆναι ἐκ τῆς ἁγίας Θεοτόκου καὶ ἀειπαρθένου Μαρίας, ἀτρέπτως ἐνανθρωπήσας, σταυρωθείς τε Χριστὲ ὁ Θεός, θανάτῳ θάνατον πατήσας, εἷς ὢν τῆς Ἁγίας Τριάδος, συνδοξαζόμενος τῷ Πατρὶ καὶ τῷ Ἁγίῳ Πνεύματι, σῶσον ἡμᾶς."
Here's the English (a very good translation):
"Only begotten Son and Word of God, although immortal You humbled Yourself for our salvation, taking flesh from the holy Theotokos and ever virgin Mary and, without change, becoming man. Christ, our God, You were crucified but conquered death by death. You are one of the Holy Trinity, glorified with the Father and the Holy Spirit-save us."
The really neat word here, in my opinion. is "σαρκωθῆναι" which literally means "enfleshed". It is also clear from the chant that the flesh came from the holy Theotokos, which in turn shows up in the Declaration of Chalcedon, which was promulgated soon after this Liturgy was established. The theological origins of this were likely in Antioch. The dogmatic statements about Christ in the Creed, about 100 years older than this liturgical text, speak of Him as being "begotten of the Father before all ages. Light of Light, true God of true God, begotten not created, of one essence with the Father through Whom all things were made. Who for us men and for our salvation came down from heaven and was incarnate of the Holy Spirit and the Virgin Mary and became man."
Here's the Greek:
Καὶ εἰς ἕνα Κύριον Ἰησοῦν Χριστόν, τὸν Υἱὸν τοῦ Θεοῦ τὸν μονογενῆ, τὸν ἐκ τοῦ Πατρὸς γεννηθέντα πρὸ πάντων τῶν αἰώνων· φῶς ἐκ φωτός, Θεὸν ἀληθινὸν ἐκ Θεοῦ ἀληθινοῦ, γεννηθέντα οὐ ποιηθέντα, ὁμοούσιον τῷ Πατρί, δι' οὗ τὰ πάντα ἐγένετο.
Τὸν δι' ἡμᾶς τοὺς ἀνθρώπους καὶ διὰ τὴν ἡμετέραν σωτηρίαν κατελθόντα ἐκ τῶν οὐρανῶν καὶ σαρκωθέντα ἐκ Πνεύματος Ἁγίου καὶ Μαρίας τῆς Παρθένου καὶ ἐνανθρωπήσαντα.
The Creed seems clear enough and yet the Nestorian heresy (Christotokos vs. Theotokos)arose despite it's apparent clarity. My point is that this is a very ancient belief in The Church and none of it is necessarily simple to anyone, especially non Greek or Arabic speakers.