Faith and Repentance
Calvin highlights "faith and repentance" many times in his catechism. One such occasion is the when he states that the "whole doctrine of the gospel is contained in these two points":
127 M. It follows from this, that Faith is the root, from which all good works originate and cannot, by any means, make us slothful about them.
C. It is true. And therefore the whole doctrine of the gospel is contained in these two points, Faith and Repentance.
Quite traditionally, Calvin says that "Faith is the root, from which all good works originate and cannot, by any means, make us slothful about them." But there is also the added element of repentance to the doctrine of the gospel. By this Calvin means "a hatred of sin and a love of righteousness, proceeding from the fear of God" (Q.128).
Later in the catechism, Calvin states concerning baptism:
"The right use of baptism is placed in faith and repentance. That is, that we first determine, by a sure confidence of soul, that we are cleansed from all spots by the blood of Christ, and are acceptable to God. Then that we believe that his Spirit dwells in us and that we make this manifest by our works among others. Also that we assiduously exercise ourselves in striving for the mortification of the flesh, and obedience to the will of God." (Q.332)
The proper use of baptism is in the "whole doctrine of the gospel." It is both the faith that God's promises are in fact true (note the presumptive nature of Calvin on the cleansing and indwelling benefits with the believer). But it is also the assiduous "mortification of the flesh."
Similarly, the inspection Calvin suggests for the Lord Supper is nothing more than "If he possesses true faith and repentance, if he exercises sincere love towards his neighbors, and if his mind is free from all hatred and malice" (Q.359). The "whole doctrine of the gospel" in Calvin's catechism is driving towards this love of God, love of neighbor, and hatred of sin.