The Jews, led by their preachers, the scribes and Pharisees, also claimed before the Lord that their God was God the Father (John 8:41) . And that was indeed what they believed. However, the Lord did not accept their claim.
As for the groups that make up Christianity today, what you are saying is that what they claim goes even further than what they say and demonstrate through their actions.
Yet the fact that they have different understandings of the Lord Jesus is already enough to show that what comes out of a person’s mouth is not necessarily what God believes to be true.
Rather, it is what is in a person’s heart, what God sees, that truly matters.
JEREMIAH 17:10
10 I the Lord search the heart, I try the reins, even to give every man according to his ways, and according to the fruit of his doings.