Bible Verses About Seed: Preaching the gospel

And he spake many things unto them in parables, saying, Behold, a sower went forth to sow;

Which indeed is the least of all seeds: but when it is grown, it is the greatest among herbs, and becometh a tree, so that the birds of the air come and lodge in the branches thereof.

If we have sown unto you spiritual things, is it a great thing if we shall reap your carnal things?