Jesus said to them, “Children, have you any fish?” They answered Him, “No.” – John 21:5

Are there any of you who fear that you have toiled in vain and spent your strength for nought? I would entreat you, dear friends, not to be satisfied with casting in the seed unless you reap some good results; yet do not be so faint-hearted as to give up because of a little disappointment. Though you cannot be satisfied without fruit, yet do not cease to sow because one season proves a failure. I would not have our friends the farmers abandon agriculture because this year they have a bad crop: if they were to measure their future prospects by the present failure, it would be a great pity. If you have preached or taught, or done work for Christ with little success until now, do not infer that you will always be unsuccessful. Regret the lack of prosperity but do not relinquish the labour of seeking it. You may reasonably be sorrowful, but you have no right to despair. Non-success is a trial of faith which has been endured by many a trusty servant who has been triumphant in the issue. Did not the disciples toil all night, and catch nothing?…Did not our Lord say that some seed would fall on stony ground, and some among the thorns, and that from these there would be no harvest? What good did Jeremiah do? I have no doubt he laboured, and God blessed him, but the result of his preaching was that he said, “The bellows are burned in the fire.” He had blown up the fire till he had burnt the bellows, but no man’s heart was melted. “Woe is me”! said he. “Oh that my head were waters, and mine eyes a fountain of tears”! I do not know what was the result of Noah’s ministry, but I do know that he was a preacher of righteousness for a hundred and twenty years, and yet he never brought a soul into the ark except his own family. Poor preaching we may count it judging by the influence it exerted: and yet we know that it was grand preaching, such as God commended. Do not, then, grudge the time, or the strength, you lay out in the service of our great Lord because you do not see your efforts thrive, for better men than you have wept over failure. ~ C.H. Spurgeon

https://www.blueletterbible.org/Comm/spurgeon_charles/sermons/1513.cfm