Contradiction with Romans 3:28
1 Peter 1:9 states salvation is through faith, while Romans 3:28 emphasizes justification without works of the law.
Romans 3:28: Therefore we conclude that a man is justified by faith without the deeds of the law.
Contradiction with James 2:24
While 1 Peter 1:9 implies faith leads to salvation, James 2:24 argues that a person is justified by works and not by faith only.
James 2:24: Ye see then how that by works a man is justified, and not by faith only.
Contradiction with Ephesians 2:8-9
Ephesians makes it clear that salvation is a gift of God not of works, whereas 1 Peter 1:9 might be read as faith being the decisive factor.
Ephesians 2:8-9: For by grace are ye saved through faith; and that not of yourselves: [it is] the gift of God: