Comment by erutuon

In English, some prayers came directly from the King James Bible. The singular second-person pronoun in those prayers corresponded with the informal second-person pronoun in the normal spoken or written English of that time. It would have been weird to change the "hallowed be thy name" written in the Bible to "hallowed be your name" when actually praying just to be more formal towards God. Being formal would also not reflect the teaching that Christians have been adopted as sons and daughters of God. I read that "thou" indicated familiarity and affection like between family members and friends and lovers, whereas "ye" indicated distance, and using "ye" towards someone that you'd normally call "thou" would indicate you had a problem with them. So calling God "ye" would require you to rephrase passages in the Bible and might connote that you don't think God has a friendly or familial sort of relationship with Christians, but is far removed from humans or even antagonistic towards them.