1 Corinthians 7:32

But I would have you without carefulness. He that is unmarried careth for the things that belong to the Lord, how he may please the Lord:

The unmarried person is free from carefulness and able to care for the things that belong to the Lord and how to please Him, devoting every interest and all the powers God has given to God's cause in saving precious souls. A man and a woman who do not marry have a better influence in missionary work. Becoming wholly engrossed in thoughts of marriage can distract young people from the work God would have them do and leave them spiritually unfit for it.

For those professedly given to missionary work, marrying and bringing children into the world greatly increases cares and burdens. That course exhausts strength and neglects personal duty, while leaving children here and there for others to care for, which is not after God's order. It cuts usefulness to one half or one third of what devoted service as a soldier of the cross would be. It would have been better for missionaries not to marry but to devote their interests to God's cause.

Those already married should thoroughly consider their situation and decide that God shall have all their powers for the work of saving souls. They should give God those undivided powers rather than laboring to bring a large number of children into the world and thereby increasing cares and burdens. Once children are brought into the world, the greatest care of the parents must and ought to be the family, even if that requires leaving the field to do duty to the children.