Contradiction with Jeremiah 17:9
Joel 2:12 implies people can return to God with all their heart, but Jeremiah 17:9 states the heart is deceitful above all things, suggesting one cannot fully trust their own heart to return sincerely.
Jeremiah 17:9: The heart [is] deceitful above all [things], and desperately wicked: who can know it?
Contradiction with Proverbs 28:26
While Joel 2:12 calls for a heartfelt return to God, Proverbs 28:26 warns against trusting one's heart, implying difficulty in fully returning with genuine intent.
Proverbs 28:26: He that trusteth in his own heart is a fool: but whoso walketh wisely, he shall be delivered.
Contradiction with Matthew 7:21
Joel 2:12 emphasizes returning to God with all your heart, but Matthew 7:21 suggests that not everyone who claims to follow God will enter heaven, emphasizing actions over heart intentions.
Matthew 7:21: Not every one that saith unto me, Lord, Lord, shall enter into the kingdom of heaven; but he that doeth the will of my Father which is in heaven.
Contradiction with Hebrews 3:12
Joel 2:12 advocates wholehearted turning to God, while Hebrews 3:12 warns believers against having an unbelieving heart that moves away from God.
Hebrews 3:12: Take heed, brethren, lest there be in any of you an evil heart of unbelief, in departing from the living God.