Contradiction with Isaiah 42:8
This verse states that God will not give His glory to another, while Matthew 12:21 mentions the Gentiles trusting in Jesus' name, implying the sharing of glory.
Isaiah 42:8: I [am] the LORD: that [is] my name: and my glory will I not give to another, neither my praise to graven images.
Contradiction with Exodus 34:14
This verse commands worship only for God, yet Matthew 12:21 implies the Gentiles will place trust in Jesus' name, which could suggest worship.
Exodus 34:14: For thou shalt worship no other god: for the LORD, whose name [is] Jealous, [is] a jealous God:
Contradiction with John 14:6
In this verse, Jesus states that no one comes to the Father except through Him, which contrasts with the idea of trust in Matthew 12:21 as it implies exclusivity rather than general trust in His name.
John 14:6: Jesus saith unto him, I am the way, the truth, and the life: no man cometh unto the Father, but by me.
Contradiction with Isaiah 45:22
This verse calls for people to be saved by turning to God alone, while Matthew 12:21 suggests the Gentiles hope in Jesus' name.
Isaiah 45:22: Look unto me, and be ye saved, all the ends of the earth: for I [am] God, and [there is] none else.
Contradiction with Jeremiah 17:5
This verse says that one is cursed who trusts in man, yet Matthew 12:21 centers on trust in Jesus' name, who is presented as a man in the incarnate form.
Jeremiah 17:5: Thus saith the LORD; Cursed [be] the man that trusteth in man, and maketh flesh his arm, and whose heart departeth from the LORD.