“Ask, and it shall be given you; seek, and ye shall find; knock, and it shall be opened unto you. For every one that asketh receiveth; and he that seeketh findeth; and to him that knocked it shall be opened.”—Matt. 7:7, 8.
“Strive to enter in at the strait gate; for many, I say unto you, will seek to enter in, and shall not be able.”—Luke 13:24.
Some have supposed a difference in the latter passage between seeking and striving; as though it were not enough to seek, without striving, even to an agony. But this does not reconcile the two passages; for seeking in the one is connected with finding, whereas in the other it is not.
The distinction appears to lie in the time and nature of seeking. Seeking, in Matthew, refers to the application for mercy through Jesus Christ, in the present life; but, in Luke, it denotes that anxiety which the workers of iniquity will discover to be admitted into heaven at the last day. The strait gate in this latter passage does not mean an introduction to the kingdom of grace, but of glory; and striving, or agonizing, to enter in at it, does not describe an exercise of mind which is necessary to conversion, but to final salvation. The striving here exhorted to is the life’s work of a Christian, in order that he may enter into the kingdom of heaven at last. All this is manifest from the context, which determines it to refer to what shall take place at the great day, “when the master of the house is risen up, and hath shut to the door, and sinners shall begin to stand without, to knock at the door, saying, Lord, Lord, open unto us; and he shall answer and say unto them, I know you not whence you are; depart from me, all ye workers of iniquity.”
There is therefore no contradiction whatever in these passages. Every one that seeketh mercy in the name of Jesus, while the door is open, succeeds; but he that seeketh it not till the door is shut will not succeed. “Then shall they call upon me, but I will not answer; they shall seek me early, but they shall not find me.”
Fuller, A. G. (1988). The Complete Works of Andrew Fuller: Memoirs, Sermons, Etc. (J. Belcher, Ed.) (Vol. 1, pp. 667–684). Harrisonburg, VA: Sprinkle Publications.