Romans 2:16--"...on the day when, according to my gospel, God will judge the secrets of men through Christ Jesus."

Men will finally be judged by their own thoughts, which either accuse them of guilt or defend them according to the good which they have done; for then not words or works, which might deceive, but their own inner-most thoughts witness concerning them publicly, just as these now witness in them, telling them what they are and what they have done. From our own (guilty) conscience certainly only accusing thoughts can come, because our works are vain before God, unless He himself is efficacious in us by His grace. We of course, may easily excuse ourselves. But that does not mean that we have satisfied God or fully kept His Law. But from whom, then, do we obtain the thoughts that (truly) excuse us? Only from Christ and in Christ; for if the conscience of a believer in Christ reproves, accuses and condemns him as an evil-doer, he quickly turns from himself to Christ and says: “He has atoned for my sins. He is just and my Justifier, who died for me. He has made His righteousness my own and my sins His own. But if He has made my sins His own, then I no longer have them but am free from them. And if He has made His righteousness my own, then I am righteous because of His righteousness, for He is God, blessed forever.” Far greater is He who defends me than that which accuses me, indeed, infinitely greater. God is my Defender, while my heart is my accuser (Luther's commentary on the Epistle to the Romans [2:16]).