Even according to your version of the events, he wasn't forthright after the Mitchell Report, but you think he decided to come clean with Congress because it was the right thing to do. If he was the good Christian that he claims to be he should have been forthright after the Mitchell Report. He didn't merely fail to disclose after the Mitchell Report. He affirmatively lied saying that he only used twice. Again, it's not something a good Christian would do. I have nothing against bad Christians. I am not a churchgoer. However, I despise religious hypocrites such as the bible-thumping Pettitte. I choose to believe that he changed his tune when Congress subpoenaed him, because the penalties for lying to Congress are severe, not because he thought it was the right thing to do.
Like you, I don't care what a player does in his personal life. However, when we are righting a guys player obit and he is called a class act, when in fact he was and is a scumbag, I will speak up. If we want to talk about him as a performer, I have no disagreement that he is a borderline HOF performer, but as a person he was not and is not a class act. If you only care about how he performed, why does it bother you that I post my opinion that he's a scumbag?
My opinion of Pettitte might change if someday he donates his liver or a kidney to a total stranger.