” It happens that the best efforts of a devoted teacher seem to be lost on many pupils. Even this will not discourage the religious teacher. 

He will remember that his model, Jesus Christ, did not reap the fruit which might have been expected from such a Master. Not all that He sowed brought forth fruit a hundredfold, not even thirtyfold. Some fell upon stony ground, and other some fell among the thorns, and yet He went on patiently sowing. 

So a teacher ought not to be disheartened if the success should not correspond with his labors. He knows that one reward is certainly in store for him, the measure of which will not be his success, but his zeal; not the fruit but his efforts.”

– Rev Daniel Lord via Finer Feminity 

It is not given to us to know exactly when or how the seeds we sow with our lessons and conversations will come to fruition.  It is not given to us the power to force growth, only to encourage it.  We do better to focus on the planting because the harvest may not be ours to see.  That does not mean it is not in the works however.