Dr. Martyn Lloyd-Jones on effectual calling

1 Corinthians 1:2 'Unto the church of God which is at Corinth to them that are sanctified in Christ Jesus, called to be saints …'. it is not simply that they are called saints, they are called to be saints. And then, in that same chapter, the Apostle repeats it. He says, 'We preach Christ crucified, unto the Jews a stumblingblock, and unto the Greeks foolishness' — then notice — 'but unto them which are called, both Jews and Greeks, Christ is the power of God, and the wisdom of God' ( 1 Cor. 1:23– 24 ). Now there are people to whom the preaching of Christ is foolishness; they are the unsaved. But the saved he again describes as those who are called .
--MLJ