By merit we mean that which is counted to one as a cause or reason deserving well. It is an accrued credit of good works that places God under obligation to reward us. If salvation or forgiveness "be of works, then it is no more grace" (Rom. 11:6. The first thing that awakened sinners think of doing is to set about to improve themselves by adding some good works on "the credit side of the ledger." Whether this is possible or not depends upon whether there can be works of supererogation. This term simply means to do more than is required by duty or obligation. Is it possible, then, to do more than is required of us as subjects of God's moral government? Is it possible to do more than our "reasonable (or logical) service?" If so, then we might lessen the grace that need be exercised in our forgiveness. If not, then forgiveness of sin is always totally of grace. (See Luke 17:7-10; Romans 12:1-2)
Our question is answered by a consideration of "what doth the Lord require of thee?"1 To please God is to "walk in the light, as He is in the light." (1 John 1:7) It is a willingness to perceive what is true in our relations to God and to our fellowmen and to fulfill our obligations as we perceive them, according to our ability. We do not seek more moral light than we are willing to obey (John 3:21). We are obligated to obey what we see, no more and no less. To obey what we see is to be acceptable to God (Acts 10:34-35). If we are "holding down the truth" (Rom. 1:18) so we do not see more, in order that our obligation will not be increased and be more exacting upon our obedience, then this in itself becomes a state of voluntary ignorance and incurs guilt.
We notice in connection with the law that all are to "love the Lord thy God with all thin heart, and with all thy soul, and with all thy might" (Deut. 6:5). The words "all thy" express our obligation. It is the exertion of "thy" personality and ability that is required - "all" this ability. Since we cannot love God with more that "all," we cannot do more than is required. Thus as time passes we may choose to fulfill our obligation or choose not to do so. When we are so choosing, we are not condemned and are not accruing guilt that needs to be forgiven. When we are not so choosing, we are adding guilt moment by moment, as the clock ticks away, accruing this guilt against us to call forth justice if mercy is not allowed to intervene. Sincere repentance may stop these additions, but can do nothing to blot out what has been done. Forgiveness must always, therefore, be entirely of unmerited grace. Its exercise can never be brought under any kind of obligation. It always proceeds from the heart of God out of pure mercy. God's sovereignty is never intruded upon. God revealed this to Moses: "I will have mercy on whom I will have mercy and I will have compassion on whom I will have compassion" (Rom. 9:15 from Ex. 33:19). However, through the blessed Gospel, God has limited His sovereignty by His promises to forgive sin upon certain conditions, which is the foundation of faith.
In this connection it should be said, that the Lord Jesus in His humanity was not free to obey in behalf of others since He could do no more than obey for Himself. He was "made of a woman, made under the law" (Gal. 4:4) and thus the words "all thy" applied also to Him. More than "all" He could not do. However, since He could say, "which of you convinceth me of sin?" (John 8:46), He was free from guilt and condemnation. Although His active obedience was for himself and thus could not be imputed to others, He was free to lay down His life for the sins of the world, and thus He did.
1 The subject of man's obligations to God and one another is more fully developed in the author's booklet The Moral Government of God.