And let us not be weary in well doing: for in due season we shall reap, if we faint not. – Galatians 6:9

If you sit down, and think of man’s inventions of error, and their novel doctrines, and how the churches have been bewitched by them, you will get into such a state of mind that you will neither sow nor reap. Just forget them. Give yourself to your holy service as if there were no winds and no clouds; and God will give you such comfort in your soul that you will rejoice before Him and be confident in His truth.

When the clouds and the winds get into your heart, when you do not feel as you used to feel, when you have not that joy and elasticity of spirit you once had, when your ardour seems a little damped, and even your faith begins to hesitate a little, go you to God all the same. Trust Him still. Do not go up and down like the mercury in the weather-glass; but know what you know and believe what you believe. Hold to it, and God keep you in one mind, so that none can turn you; for, if not, if you begin to notice these things, you will neither sow nor reap.

Let us follow the Lord’s mind and come what will. In a word, set your face, like a flint, to serve God, by the maintenance of His truth, by your holy life, by the savour of your Christian character; and, that being done, defy earth and hell. If there were a crowd of devils between you and Christ, kick a lane through them by holy faith. They will fly before you. If you have but the courage to make an advance, they cannot stop you. You shall make a clear gangway through legions of them. Only be strong, and of good courage, and do not regard even the clouds from hell, or the blasts from the infernal pit; but go straight on in the path of right, and God being with you, you shall sow, and you shall reap, unto His eternal glory. ~ C.H. Spurgeon

https://www.blueletterbible.org/comm/spurgeon_charles/sermons/2264.cfm