Heidelberg Catechism Q&A #21:
What is Faith?
True faith - created in me by the Holy Spirit through the Gospel- is not only a knowledge and conviction that everything that God reveals in His Word is true, but also a deep-rooted assurance that not only others, but I too, have had my sins forgiven, have been made forever right with God, and have been granted salvation. These are the gifts of sheer grace earned for us by Christ.