I believe no true Christian can be satisfied with a notional religion--though a miserable backslider, and driven into the fields to feed swine, he cannot feed on their husks, but sighs after the bread of his Father's house. The eyes being enlightened to see the nature of sin, the justice and holiness of God, and the miserable filthiness of self, the quickened soul can find no rest in anything short of a precious discovery of the Lamb of God; and the more that the soul is exercised with trials, difficulties, temptations, doubts, and besetments of various kinds, the more does it feel its need of that blood of sprinkling that speaks better things than that of Abel.
What is a Christian worth without inward trials and afflictions? How dead and lifeless are our prayers; how cold and formal when the soul is not kept alive by inward exercises! Where are the sighs, cries, groanings, wrestlings, and breathings of a soul that is at ease in Zion? The world is everything and Christ nothing, when we become settled on our lees, and are not emptied from vessel to vessel; but inward exercises, fears, straits, and temptations stir up the soul to cry, and pray, and beg for mercy. The certainty, the power, the reality of eternal things are then felt--when guilt, and wrath, and fear, and disquietude lay hold of the soul.
Mere notions alone of Christ, false hope, a dead faith, a presumptuous confidence, a rotten assurance, are all swept away as so many refuges of lies, when the soul is made to feel its nakedness and nothingness, its guilt and helplessness before God. And thus all these inward exercises pave the way for discoveries of Christ--those views of his blood and righteousness, that experimental acquaintance with his Person, love, grace, and work, which is life and peace.