"It is easy to conclude, when things turn out badly, that it was all a mistake to begin with.
The facts of the gospel do not bear this out. Think of Jesus' choice of apostles. He spent a whole night in prayer before He made his selection. Judas was one of his choices. Peter affirmed, in his sermon on the day of Pentecost, "He was one of our number and had his place in this ministry" (Acts 1:17 NEB). Things could not have turned out worse for him or for Jesus because of him, yet Scripture nowhere suggests that the original choice was a mistake. Judas was still a man, still free to sin.
When we must make decisions, we should bring to bear on them scriptural principles, prayer, and all the intelligence God has dealt out to us. Then we must go on quietly in faith, knowing that the results of our obedience are God's responsibility, not ours."
~excerpt from A Lamp Unto My Feet by Elisabeth Elliot, page 165