"So then neither is he that planteth anything, neither he that watereth, but God that giveth the increase." (1 Corinthians 3:7)
This verse is a salutary corrective to the common somewhat boastful claim of the evangelist or the personal "soul winner"--that "I won John to Christ," or "I led Mary to the Lord." On the other side of the coin is the similar man-pleasing testimony that "I was won to Christ by Pastor Brown's sermons." While it is commanded and is urgently important that each Christian be a faithful and earnest witness for Christ, it is needful to give God alone the credit for one's salvation, since it is only He "that giveth the increase." We can be grateful whenever God uses something we have preached or written or said to bring someone to Himself, but He is by no means limited to such human efforts, and it is the sin of pride to take credit for what only the Holy Spirit can accomplish.
The Christian's ministry is necessarily limited to "planting" and "watering," but these constitute a tremendous responsibility and is a privilege of eternal value. And even these are productive only if centered around the Holy Scriptures, because both the seed which is planted and the water which enables it to grow are said to be the word of God. Even the great evangelist, the apostle Paul, must say: "I have planted, Apollos watered; but God gave the increase" (1 Corinthians 3:6).
Nevertheless, we do have many gracious promises that, if we are faithful in planting and watering, God will give the increase, and we can share His joy. "He that goeth forth and weepeth, bearing precious seed, shall doubtless come again with rejoicing, bringing his sheaves with him" (Psalm 126:6). "For whatsoever a man soweth, that shall he also reap" (Galatians 6:7). HMM