This song meaning is, that God sees what we do, and when Judgement Day comes, he is scared to find out what side he is on, but he's hoping hes on God's side. God tried to help people for thousand ages, but people did not listen, so they died. In line 14-15, its talking about, how can someone just sit by and watch others murder, and he's talking to God, as in, why should God let him live? Then God says he will spare him, because he loves us, and wants us not to judge by what someone has done, In lines19-29, he is asking God, to take away his sins, and wants to know what will happen if he does all of these bad things, and God says that he will forgive him, only if he asks for forgivness.
And God forgave him and saved him, and now he lives and fights for God.