What is effectual calling?
Effectual calling is the work of God’ s almighty power and grace, (John 5:25, Eph. 1:18–20, 2 Tim. 1:8–9) whereby (out of his free and special love to his elect, and from nothing in them moving him thereunto) (Tit. 3:4–5, Eph. 2:4–5,7–9, Rom. 9:11) he doth, in his accepted time, invite and draw them to Jesus Christ, by his word and Spirit; (2 Cor. 5:20, 2 Cor. 6:1–2, John 6:44, 2 Thess. 2:13–14) savingly enlightening their minds, (Acts 26:18, 1 Cor. 2:10,12) renewing and powerfully determining their wills, (Ezek. 11:19, Ezek. 36:26–27, John 6:45) so as they (although in themselves dead in sin) are hereby made willing and able freely to answer his call, and to accept and embrace the grace offered and conveyed therein. (Eph. 2:5, Phil. 2:13, Deut. 30:6)
The Westminster Larger Catechism: With Scripture Proofs. (Oak Harbor, WA: Logos Research Systems, Inc., 1996).