Contradiction with Jeremiah 17:1
This verse suggests that sins are permanently inscribed, contradicting the idea of sins being removed as far as the east is from the west.
Jeremiah 17:1: The sin of Judah [is] written with a pen of iron, [and] with the point of a diamond: [it is] graven upon the table of their heart, and upon the horns of your altars; [point: Heb. nail]
Contradiction with Hebrews 10:26-27
This passage implies that willful sin remains and expects judgment, contrasted with sins being taken away completely.
Hebrews 10:26-27: For if we sin wilfully after that we have received the knowledge of the truth, there remaineth no more sacrifice for sins,
Contradiction with Numbers 32:23
This verse states that sin will find you out, opposing the idea of sins being forgotten or removed.
Numbers 32:23: But if ye will not do so, behold, ye have sinned against the LORD: and be sure your sin will find you out.
Contradiction with 1 Corinthians 6:9-10
This passage lists sins that will prevent entry into the kingdom of God, suggesting they have lasting consequences unlike in Psalms 103:12.
1 Corinthians 6:9-10: Know ye not that the unrighteous shall not inherit the kingdom of God? Be not deceived: neither fornicators, nor idolaters, nor adulterers, nor effeminate, nor abusers of themselves with mankind,
Contradiction with Exodus 34:7
It mentions God visiting iniquity onto future generations, implying sins are not entirely removed.
Exodus 34:7: Keeping mercy for thousands, forgiving iniquity and transgression and sin, and that will by no means clear [the guilty]; visiting the iniquity of the fathers upon the children, and upon the children's children, unto the third and to the fourth [generation].