And straightway the father of the child cried out, and said with tears, “Lord, I believe; help Thou mine unbelief.” -Mark 9:24

With tears he said, “Lord, I believe,” and then acknowledged his unbelief. Learn then, dear hearer, always to look at unbelief in Christ in the light of a fault. Never say, “This is my infirmity,” but say, “This is my sin.” There has been too much in the Church of God of regarding unbelief as though it were a calamity commanding sympathy, rather than a fault demanding censure as well. I am not to say to myself, “I am unbelieving, and therefore I am to be pitied.” No, “I am unbelieving, and therefore I must blame myself for it.” Why should I disbelieve my God? How dare I doubt Him who cannot lie? How can I mistrust the faithful promiser who has added to His promise His oath, and over and above His promise and His oath has given His own blood as a seal, that by two immutable things, wherein it was impossible for God to lie, we might have strong consolation. Chide yourselves, ye doubters. Doubts are among the worst enemies of your souls. Do not entertain them. Do not treat them as though they were poor forlorn travelers to be hospitably entertained, but as rogues and vagabonds to be chased from thy door. Fight them, slay them, and pray God to help thee to kill them, and bury them, and not even to leave a bone or a piece of a bone of a doubt above ground. Doubting and unbelief are to be abhorred, and to be confessed with tears as sins before God. We need pardon for doubting as much as for blasphemy. We ought no more to excuse doubting than lying, for doubting slanders God and makes Him a liar.~ C.H. Spurgeon

https://www.blueletterbible.org/Comm/spurgeon_charles/sermons/1033.cfm