The theology of kneeling is explained by Joseph Cardinal Ratzinger, the Prefect of the Congregation for the Doctrine of the Faith, in the following excerpt from a chapter, “The Body and the Liturgy”, in The Spirit of the Liturgy.
adoremus.org/1102TheologyKneel.html
"There are groups, of no small influence, who are trying to talk us out of kneeling. “It doesn’t suit our culture”, they say (which culture?) “It’s not right for a grown man to do this – he should face God on his feet”. Or again: “It’s not appropriate for redeemed man – he has been set free by Christ and doesn’t need to kneel any more”.
If we look at history, we can see that the Greeks and Romans rejected kneeling…
Aristotle called it a barbaric form of behavior (cf. Rhetoric 1361 a 36). Saint Augustine agreed with him in a certain respect: the false gods were only the masks of demons, who subjected men to the worship of money and to self-seeking, thus making them “servile” and superstitious. He said that the humility of Christ and His love, which went as far as the Cross, have freed us from these powers. We now kneel before that humility.
The kneeling of Christians is not a form of inculturation into existing customs. It is quite the opposite, an expression of Christian culture, which transforms the existing culture through a new and deeper knowledge and experience of God.
**Kneeling does not come from any culture – it comes from the Bible and its knowledge of God. **The central importance of kneeling in the Bible can be seen in a very concrete way. The word proskynein alone occurs fifty-nine times in the New Testament, twenty-four of which are in the Apocalypse, the book of the heavenly Liturgy, which is presented to the Church as the standard for her own Liturgy.