Can we be sure that the thief on the cross understood the biblical definition of sin. It would have to be at least only an ‘Old Testament’ definition, would it not? The New Testament having not yet been written when he entered paradise.
Lu 23:40 But the other answering rebuked him, saying, Dost not thou fear God, seeing thou art in the same condemnation?
Lu 23:41 And we indeed justly; for we receive the due reward of our deeds: but this man hath done nothing amiss.
the thief knew he was a sinner.