Though believing in Christ is a compliance with a duty, yet it is not as a duty, or by way of reward for a virtuous act, that we are said to be justified by it. It is true God does reward the services of his people, as the Scriptures abundantly teach; but this follows upon justification. We must stand accepted in the Beloved, before our services can be acceptable or rewardable. Moreover, if we were justified by faith as a duty, justification by faith could not be, as it is, opposed to justification by works: “To him that worketh is the reward not reckoned of grace, but of debt. But to him that worketh not, but believeth on him that justifieth the ungodly, his faith is counted for righteousness.” The Scripture doctrine of justification by faith, in opposition to the works of the law, appears to me as follows: By believing in Jesus Christ, the sinner becomes vitally united to him, or, as the Scriptures express it, “joined to the Lord,” and is of “one spirit with him;” and this union, according to the Divine constitution, as revealed in the gospel, is the ground of an interest in his righteousness. Agreeable to this is the following language: “There is now, therefore, no condemnation to them that are in Christ Jesus.”—“Of him are ye in Christ Jesus, who of God is made unto us righteousness,” &c.—“That I may be found in him, not having mine own righteousness which is of the law, but that which is through the faith of Christ.” As the union which, in the order of nature, precedes a revealed interest in Christ’s righteousness, is spoken of in allusion to that of marriage, the one may serve to illustrate the other. A rich and generous character, walking in the fields, espies a forlorn female infant, deserted by some unfeeling parent in the day that it was born, and left to perish. He sees its helpless condition, and resolves to save it. Under his kind patronage the child grows up to maturity. He now resolves to make her his wife; casts his skirt over her, and she becomes his. She is now, according to the public statutes of the realm, interested in all his possessions. Great is the transition! Ask her, in the height of her glory, how she became possessed of all this wealth; and, if she retain a proper spirit, she will answer in some such manner as this: It was not mine, but my deliverer’s; his who rescued me from death. It is no reward of any good deeds on my part; it is by marriage; … it is “of grace.”
It is easy to perceive, in this case, that it was necessary she should be voluntarily married to her husband, before she could, according to the public statutes of the realm, be interested in his possessions; and that she now enjoys those possessions by marriage: yet who would think of asserting that her consenting to be his wife was a meritorious act, and that all his possessions were given her as the reward of it?
Excerpt from: “Concluding Reflections,” in The Gospel Worthy of All Acceptation.”
Fuller, A. G. (1988). The Complete Works of Andrew Fuller: Controversial Publications. (J. Belcher, Ed.) (Vol. 2, p. 384). Harrisonburg, VA: Sprinkle Publications.