And they said, Believe on the Lord Jesus Christ, and thou shalt be saved, and thy house. – Acts 16:31

Hast thou seen no children converted? Fear not,

“Though seed lie buried long in dust,
It shan’t deceive your hope,
The precious grain can ne’er be lost,
For God insures the crop.”

Go on sowing still, and thou shalt have a harvest when thou shalt see children converted. I have known some Sabbath-school teachers who could count a dozen, or twenty, or thirty children, who have, one after another, come to know the Lord Jesus Christ, and to join the church. But if you should not live to see it on earth, remember you are only accountable for your labor, and not for your success. Sow still, toil on! “Cast thy bread upon the waters: for thou shalt find it after many days.” God will not allow His Word to be wasted; it shall not return unto Him void, but shall accomplish that which He pleases. There may be a harvest to a poor mother who has often been sad. She has a son and a daughter, and she has been always praying that God might convert their souls. Mother, thy son is an ungainly boy still; he grieves thy heart; still the hot tears scald thy cheeks on account of him. And thou, father, thou hast reproved him often; he is a wayward son, and he is still running the downward road. Cease not to pray! O my brethren and sisters, who are parents, you shall have a harvest! What thinkest thou, mother, wouldst thou not rejoice to see thy son a minister of the gospel; thy daughter teaching and assisting in the cause of God? God will not suffer thee to pray, and thy prayers be unheeded. ~ C.H. Spurgeon

https://www.blueletterbible.org/Comm/spurgeon_charles/sermons/2896.cfm