Problem: Peter writes that Psalm 118:22 predicts the rejection of Christ. Is Peter properly citing this passage, or is he tearing it from its original context?
Solution: In Psalm 118, the surrounding nations are “cut off” from the blessings of God (v.10-12), but God has saved the psalmist from this destruction (v.14, 17). While the psalmist thanks God for his salvation (v.21), he notices that others have rejected this salvation (v.22). This is the passage that Peter quotes. Peter isn’t claiming that Psalm 118:22 is a prediction of Christ. Instead, he is demonstrating how people currently forfeit salvation because of their unbelief. Peter is simply trying to show a connection between forfeiting God’s blessings because of unbelief.