Galatians Chapter 1:
6: I marvel that ye are so soon removed from him that called you into the grace of Christ unto another gospel:
7: Which is not another; but there be some that trouble you, and would pervert the gospel of Christ.
8: But though we, or an angel from heaven, preach any other gospel unto you than that which we have preached unto you, let him be accursed.
9: As we said before, so say I now again, If any man preach any other gospel unto you than that ye have received, let him be accursed.
10: For do I now persuade men, or God? or do I seek to please men? for if I yet pleased men, I should not be the servant of Christ.
11: But I certify you, brethren, that the gospel which was preached of me is not after man.
12: For I neither received it of man, neither was I taught it, but by the revelation of Jesus Christ.
So then that is the false gospel that Paul was talking about. With the true gospel we have a pardon by the death of Messiah, and not a declaration of innocence.