Make sure to pray as you were taught. In secret, and after forgiving everyone and asking for forgiveness.
As for the second statement, knowledge of that comes through being able to discern. I don't like to play copy/paste with the Word because if I do that I can make it look like God said anything I want to say He said. The more you understand the Word, the better you become at discernment. You will not be able to understand the Word unless you give your heart to Jesus, though (even if you understand the words you read). It seems you have already done that.
It should be noted that a carnal mind is firmly under Satan's control, and we should still repent for our bad thoughts. The reasons we should repent of them are not as simple as they appear, though. Everything is connected.