Contradiction with Proverbs 4:25-27
While Jeremiah 31:21 encourages setting up markers and focusing on the path back, Proverbs advises to look straight ahead and avoid turning, which could imply not looking back at markers or returning paths.
Proverbs 4:25-27: Let thine eyes look right on, and let thine eyelids look straight before thee.
Contradiction with Isaiah 43:18
Jeremiah 31:21 encourages remembrance and markers for the past journey, whereas Isaiah 43:18 advises forgetting former things and not dwelling on the past.
Isaiah 43:18: Remember ye not the former things, neither consider the things of old.
Contradiction with Philippians 3:13
In contrast to Jeremiah's call to set markers for the way back, Philippians 3:13 emphasizes forgetting what is behind and straining toward what is ahead, which contradicts the idea of retracing steps.
Philippians 3:13: Brethren, I count not myself to have apprehended: but [this] one thing [I do], forgetting those things which are behind, and reaching forth unto those things which are before,