Contradiction with Genesis 11:9
Unlike Joshua 22:30, which describes reconciliation and understanding, Genesis 11:9 depicts confusion and division at Babel.
Genesis 11:9: Therefore is the name of it called Babel; because the LORD did there confound the language of all the earth: and from thence did the LORD scatter them abroad upon the face of all the earth. [Babel: that is, Confusion]
Contradiction with Luke 12:51
Contradicting the peace in Joshua 22:30, Luke 12:51 speaks of division brought by Jesus.
Luke 12:51: Suppose ye that I am come to give peace on earth? I tell you, Nay; but rather division:
Contradiction with Matthew 10:34
While Joshua 22:30 shows an effort to avoid conflict, Matthew 10:34 mentions Jesus bringing a sword, representing conflict.
Matthew 10:34: Think not that I am come to send peace on earth: I came not to send peace, but a sword.
Contradiction with James 3:16
Unlike the resolution and peace in Joshua 22:30, James 3:16 speaks of confusion and evil in environments of strife.
James 3:16: For where envying and strife [is], there [is] confusion and every evil work. [confusion: Gr. tumult, or, unquietness]
Contradiction with Galatians 5:15
Contrasting with the unity in Joshua 22:30, Galatians 5:15 warns about consuming one another, implying conflict.
Galatians 5:15: But if ye bite and devour one another, take heed that ye be not consumed one of another.
Contradiction with Proverbs 6:16-19
While Joshua 22:30 illustrates understanding, Proverbs 6:16-19 lists things God hates, including sowing discord.
Proverbs 6:16-19: These six [things] doth the LORD hate: yea, seven [are] an abomination unto him: [unto...: Heb. of his soul]
Contradiction with 1 Corinthians 1:10
Joshua 22:30 showcases harmony, whereas 1 Corinthians 1:10 implies disunity needing an exhortation for unity.
1 Corinthians 1:10: Now I beseech you, brethren, by the name of our Lord Jesus Christ, that ye all speak the same thing, and [that] there be no divisions among you; but [that] ye be perfectly joined together in the same mind and in the same judgment. [divisions: Gr. schisms]
Contradiction with Matthew 5:9
Differing from Joshua 22:30's peaceful resolution, Matthew 5:9 calls peacemakers blessed, indicating some do not pursue peace.
Matthew 5:9: Blessed [are] the peacemakers: for they shall be called the children of God.