Contradiction with Matthew 5:44
This verse contradicts 2 Kings 2:25 because it teaches to love your enemies and bless those who curse you, whereas 2 Kings 2:25 involves a response to mockery that is not about love or blessing.
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 Romans 12:19
This verse advises against taking revenge and instead leaving it to God, whereas 2 Kings 2:25 describes a situation with a punitive response.
Romans 12:19: Dearly beloved, avenge not yourselves, but [rather] give place unto wrath: for it is written, Vengeance [is] mine; I will repay, saith the Lord.
Contradiction with Luke 6:27-28
These verses encourage doing good to those who hate you and blessing those who curse you, which contrasts with the action taken in 2 Kings 2:25.
Luke 6:27-28: But I say unto you which hear, Love your enemies, do good to them which hate you,