WSC Q.29: How are we made partakers of the redemption purchased by Christ?
We are made partakers of the redemption purchased by Christ, by the effectual application of it to us, (John 1:11–12) by his Holy Spirit. (Titus 3:5–6)
WLC Q.58: How do we come to be made partakers of the benefits which Christ hath procured?
We are made partakers of the benefits which Christ hath procured, by the application of them unto us, (John 1:11–12) which is the work especially of God the Holy Ghost. (Tit. 3:5–6)
WCF 8.8.
To all those for whom Christ hath purchased redemption, he doth certainly and effectually apply and communicate the same; (John 6:37, 39, John 10:15–16) making intercession for them, (1 John 2:1–2, Rom. 8:34) and revealing unto them, in and by the word, the mysteries of salvation; (John 15:13, 15, Eph. 1:7–10, John 17:6) effectively persuading them by his Spirit to believe and obey, and governing their hearts by his word and Spirit; (John 14:16, Heb. 12:2, 2 Cor. 4:13, Rom. 8:9, 14, Rom. 15:18–19, John 17:17) overcoming all their enemies by his almighty power and wisdom, in such manner, and ways, as are most consonant to his wonderful and unsearchable dispensation. (Ps. 110:1, 1 Cor. 15:25–26, Mal. 4:2–3, Col. 2:15)