And how shall they preach, except they be sent? – Romans 10:14

Last Tuesday night, there were a mother and father who had a son about whom they had once been very hopeful; but he had left home, and gone away for weeks, though he promised to return. He had gone off, and they had not heard a word about him. They came to a company of Christian people, last Tuesday night, broken-hearted. They had done their best to find their son, but they could not find him.

It was to Haddon Hall that they came, and the people of God there prayed for his father and mother. The father himself prayed, and broke down with emotion about his lost son. He went home, and there was a letter from his son to say that the Savior had found him. He had given up the drink, and he hoped to be a comfort to his father and mother all the rest of their days. He was many miles away, and knew nothing of his father’s prayer.

Often, when you do not get on with people, go and tell the Lord Jesus Christ about it; say, “Lord, I have preached to them, I have prayed for them, I have talked to them, I have wept over them, I bear them on my heart as a burden. Their very name seems to burn itself with letters of fire into my soul. Lord, save them! Lord, save them, and they will be saved!” That is the way to win souls. If God works, He first of all makes us travail in birth for the souls of others, and then are they born into the kingdom. ~ C.H. Spurgeon

https://www.blueletterbible.org/comm/spurgeon_charles/sermons/2327.cfm