A:The tension between God's ultimate plan in Jesus' death and Pilate's sinfulness in sentencing him to crucifixion is beautifully expressed in John 19:10-11:
"Do you refuse to speak to me?" Pilate said. "Don't you realize I have power either to free you or to crucify you?" Jesus answered, "You would have no power over me if it were not given to you from above. Therefore the one who handed me over to you is guilty of a greater sin."
A couple of things are notable about these verses. First, Jesus clearly expresses the sovereignty of his heavenly Father over the events that are transpiring. The only reason Pilate has any power over Jesus, and even any power at all, is because it has been gifted to him by God. God's plan of salvation by means of Jesus' death, however, does not clear Pilate of the legal and moral responsibility that he has to release a clearly innocent man. The Jews who have handed Jesus over to Pilate are guilty of a "greater sin," but Pilate is sinning nevertheless. This is why Jesus foretells that he will "be delivered into the hands of sinful men, be crucified and on the third day be raised again" (Luke 24:7). These sinful men include Pilate.
On a broader scale, Scripture teaches that God can use even our sinful acts for his good purposes. When Joseph becomes a leader in Egypt after being sold into slavery by his brothers, he reminds them: "As for you, you meant evil against me, but God meant it for good, to bring it about that many people should be kept alive" (Genesis 50:20). Such is the case with the cross. God uses the evil intentions of evil men as they kill his Son to bring about the salvation of the world (cf. Acts 2:22-24).