Martyn Lloyd-Jones
Why is it that some have believed? It is because the Spirit has sanctified them, has set them apart, has called them out. It is the work of the Spirit in conviction, and calling out, and giving power to believe.

At the same time, pray also for us, that God may open to us a door for the word, to declare the mystery of Christ, on account of which I am in prison— that I may make it clear, which is how I ought to speak.
Colossians 4:3-4