It is not the work of the Spirit to produce doubts and fears, but to overcome them. And yet we are continually subject to them. Infidel thoughts fly across the mind; doubts and questionings suggest themselves Satan is busy in plying his arguments; a guilty conscience falls too readily under his accusations; painful recollections of past slips, falls, and backslidings strengthen the power of unbelief, so that to come to a spot wherein there is not the least shadow of a doubt of divine realities, and, what is far more, of our own interest in them, is a rare circumstance, and only attainable at those favoured moments when the Lord is pleased to shine into the soul and settle the matter between himself and our conscience. But these very doubts, these very questionings, these cutting, killing fears, these anxious surmisings work together for good, and are mercifully overruled for our spiritual benefit.
What else has brought us to this point that nothing short of demonstration will satisfy the soul really born and taught of God? It must have demonstration: nothing else will do. We cannot live and die upon uncertainties. It won't do to be always in a state that we don't know whether we are going to heaven or hell; to be tossed up and down on a sea of uncertainty, scarcely knowing who commands the ship, what is our destination, what our present course, or what will be the end of the voyage. Now all human wisdom leaves us upon this sea of uncertainty. It is useful in nature, but useless in grace. It is foolish and absurd to despise all human learning, wisdom, and knowledge. Without them we should be a horde of wild, wandering savages. But it is worse than foolish to make human wisdom our guide to eternity, and make reason the foundation of our faith or hope. What you thus believe today, you will disbelieve to-morrow; all the arguments that may convince your reasoning mind, all the appeals to your natural passions, which may seem for the time to soften your heart, and all the thoughts swaying to and fro which may sometimes lead you to hope you are right and sometimes make you fear you are wrong,—all these will be found insufficient when the soul comes into any time of real trial and perplexity.
We want, therefore, demonstration to remove and dispel all these anxious questionings, and settle the whole matter firmly in our heart and conscience; and this nothing can give us but the Spirit by revealing Christ, taking of the things of Christ, and shewing them unto us, applying the word with power to our hearts, and bringing the sweetness, reality, and blessedness of divine things into our soul. It is only in this way that he overcomes all unbelief and infidelity, doubt and fear, and sweetly assures us that all is well between God and the soul.