"There are some who stumble at Christ because of his holiness. He is too strict for them; they would like to be Christians, but they cannot renounce their sensual pleasures; they would like to be washed in his blood, but they desire still to roll in the mire of sin.
Willing enough the mass of men would be to receive Christ, if, after receiving him, they might continue in their drunkenness, their wantonness, and self-indulgence. But Christ lays the axe at the root of the tree; he tells them that these things must be given up, for “because of these things the wrath of God comes upon the children of disobedience,” and “without holiness no man can see the Lord.”
Human nature kicks at this. “What! May I not enjoy one darling lust? May I not indulge myself at least now and then in these things? Must I altogether forsake my old habits and my old ways? Must I be made a new creature in Christ Jesus?”
These are terms too hard, conditions too severe, and so the human heart goes back to the flesh pots of Egypt... Christ offends men because HIS GOSPEL IS INTOLERANT OF SIN."
Taken from Spurgeon's message, "Unbelievers Stumbling; Believers Rejoicing" - Metroplitan Tabernacle Pulpit, 1864