Contradiction with Philippians 4:4
While Lamentations 3:51 speaks of overwhelming sorrow affecting the heart, Philippians 4:4 urges continual rejoicing in the Lord.
Philippians 4:4: Rejoice in the Lord alway: [and] again I say, Rejoice.
Contradiction with 1 Thessalonians 5:16-18
Lamentations 3:51 reflects deep personal grief, but this verse encourages constant joy, prayer, and gratitude.
1 Thessalonians 5:16-18: Rejoice evermore.
Contradiction with Proverbs 15:13
Lamentations 3:51 implies sorrow that affects the heart negatively, whereas Proverbs 15:13 suggests a cheerful heart brings a positive external expression.
Proverbs 15:13: A merry heart maketh a cheerful countenance: but by sorrow of the heart the spirit is broken.