WSC Q.30: How doth the Spirit apply to us the redemption purchased by Christ?
The Spirit applieth to us the redemption purchased by Christ, by working faith in us, (Eph. 1:13–14, John 6:37–39, Eph. 2:8) and thereby uniting us to Christ in our effectual calling. (Eph. 3:17, 1 Cor. 1:9)