Contradiction with Exodus 23:32-33
These verses advise against making covenants with the inhabitants of the land, suggesting separation rather than cleaving as advised in Joshua 23:8.
Exodus 23:32-33: Thou shalt make no covenant with them, nor with their gods.
Contradiction with 2 Kings 17:15
This verse mentions that the people rejected God's statutes, contrasting the encouragement in Joshua 23:8 to cleave unto the Lord.
2 Kings 17:15: And they rejected his statutes, and his covenant that he made with their fathers, and his testimonies which he testified against them; and they followed vanity, and became vain, and went after the heathen that [were] round about them, [concerning] whom the LORD had charged them, that they should not do like them.
Contradiction with Galatians 1:6
This verse discusses turning away from the gospel, contrasting with steadfastness to the Lord in Joshua 23:8.
Galatians 1:6: I marvel that ye are so soon removed from him that called you into the grace of Christ unto another gospel:
Contradiction with 2 Corinthians 6:14
Advises not being unequally yoked with unbelievers, which contrasts with the idea of cleaving or holding fast to diverse groups as implied in the surrounding text of Joshua 23.
2 Corinthians 6:14: Be ye not unequally yoked together with unbelievers: for what fellowship hath righteousness with unrighteousness? and what communion hath light with darkness?