The Heidelberg Catechism, This Lord's Day week 7

Q20: Are all men, then, saved by Christ as they have perished in Adam?

A20: No, only those who by true faith are ingrafted into Him and receive all His benefits.[1]
1. John 1:12-13; I Cor. 15:22; Psa. 2:12; Rom. 11:20; Heb. 4:2-3; 10:39

Q21: What is true faith?

A21: True faith is not only a sure knowledge, whereby I hold for truth all that God has revealed to us in His Word,[1] but also a hearty trust,[2] which the Holy Ghost [3] works in me by the Gospel,[4] that not only to others, but to me also, forgiveness of sins, everlasting righteousness, and salvation are freely given by God,[5] merely of grace, only for the sake of Christ's merits.[6]
1. James 1:62. Rom. 4:16-18; 5:13. II Cor. 4:13; Phil. 1:19, 29
4. Rom. 1:16; 10:175. Heb. 11:1-2; Rom. 1:176. Eph. 2:7-9; Rom. 3:24-25; Gal. 2:16; Acts 10:43

Q22: What, then, is necessary for a Christian to believe?

A22: All that is promised us in the Gospel,[1] which the articles of our catholic, undoubted Christian faith teach us in summary.
1. John 20:31; Matt. 28:20; II Peter 1:21; II Tim. 3:15

Q23: What are these articles?

A23: I believe in God the Father Almighty, Maker of heaven and earth. And in Jesus Christ, His only begotten Son, our Lord: who was conceived by the Holy Ghost, born of the virgin Mary, suffered under Pontius Pilate, was crucified, dead and buried; He descended into hell; the third day He rose from the dead; He ascended into heaven, and sitteth at the right hand of God the Father Almighty; from thence He shall come to judge the living and the dead.
I believe in the Holy Ghost, the Holy Catholic Church, the communion of saints, the forgiveness of sins, the resurrection of the body, and the life everlasting.