We should care for our teachers, not grudgingly or reluctantly, but with a generous spirit, showing honor and appreciation for all they have done. It would certainly be a surprise if you planted corn and pumpkins came up. It's a natural law to reap what we sow. It's true in other areas too. If you gossip about your friends, you will lose their friendship.
Every action has results.
If you plant to please your own desires, you'll reap a crop of sorrow and evil. If you plant to please God, you'll reap joy and everlasting life. It is discouraging to continue to do right and receive no word of thanks or see no tangible results. But Paul challenged the Galatians and he challenges us to keep on doing good and to trust God for the results. In due time, we will reap a harvest of blessing.