Contradiction with Philippians 2:3-4
Whereas Jeremiah 48:18 speaks to the downfall and humbling of Moab, Philippians 2:3-4 encourages humility and selflessness, which suggests uplifting others rather than taking pleasure in their humbling.
Philippians 2:3-4: [Let] nothing [be done] through strife or vainglory; but in lowliness of mind let each esteem other better than themselves.
Contradiction with Matthew 5:44
This verse advises to love your enemies and pray for those who persecute you, which contrasts with the notion of celebrating the fall of Moab as described in Jeremiah 48:18.
Matthew 5:44: But I say unto you, Love your enemies, bless them that curse you, do good to them that hate you, and pray for them which despitefully use you, and persecute you;
Contradiction with Proverbs 24:17
Directly contrasts with rejoicing over the downfall of enemies as it advises not to rejoice when your enemy falls.
Proverbs 24:17: Rejoice not when thine enemy falleth, and let not thine heart be glad when he stumbleth:
Contradiction with Ezekiel 18:23
Whereas Jeremiah speaks to the downfall, Ezekiel suggests that God takes no pleasure in the death of the wicked but prefers repentance.
Ezekiel 18:23: Have I any pleasure at all that the wicked should die? saith the Lord GOD: [and] not that he should return from his ways, and live?