The Westminster Shorter Catechism
Q. 87. What is repentance unto life?
A. Repentance unto life is a saving grace, whereby a sinner, out of a true sense of his sin, and apprehension of the mercy of God in Christ, doth, with grief and hatred of his sin, turn from it unto God, with full purpose of, and endeavour after, new obedience.
The Westminster Shorter Catechism in Modern English:
Q.87. What is repentance unto life?
A. Repentance unto life is a saving grace, by which a sinner, being truly aware of his sinfulness, understands the mercy of God in Christ, grieves for and hates his sins, and turns from them to God, fully intending and striving for a new obedience.
1. Why is repentance called a "saving grace?"
It is called a saving grace because it is inseparably a part of salvation and is worked in the heart of the sinner by the Holy Spirit through the instrument of the Word of God.
2. Who is the subject of repentance?
The sinner is the subject of it for the person who is saved needs no repentance as is taught in Luke 15:7.
3. What is meant in this question by "a true sense of sin?"
A true sense of sin is the recognition on the part of the sinner of the danger of his position along with the filthiness of his sin. He knows he is in danger because he knows his sinful condition is contrary to God's holiness and is offensive to God.
4. Why is the mercy of God connected with Christ?
The mercy of God is connected with Christ because God's mercy extends to the sinner through the obedience and satisfaction of Christ in His death on the cross.
5. Is it possible for repentance to be separated from faith?
No, it is not possible to separate the two. These are both by the grace of God and therefore can be distinguished, but can not be separated.
6. What is this hatred of sin mentioned here?
It is both the loathing of sin and ourselves because of that sin (Isaiah 6:5).
7. What is this new obedience to which the repentant person turns?
It is the obedience as is found in the Gospel and proceeds from the new nature in man. The new man recognises that he must have a new purpose, a new way of walking. He will not be perfect but he will be diligent in his endeavours to walk after righteousness.