Pilate tried to prove his innocence by washing his hands, but his sin could not be taken away by washing. The only thing that can wash away sin is the blood of Jesus and trusting in His death, burial and resurrection. Pilate was guilty of helping to send Jesus to the cross, but God used him to fulfill prophecy.
Matthew 27:24 When Pilate saw that he could prevail nothing, but that rather a tumult was made, he took water, and washed his hands before the multitude, saying, I am innocent of the blood of this just person: see ye to it.
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