Many times we see and hear people say come to church and God will give you this or that. It is now so common to have people call themselves ‘Christians’ and yet they have never heard of sin and righteousness. So you ask, ‘Is there anything wrong with that?’ Well you see the knowledge of sin comes after you know what the law of God is – for sin is lawlessness toward God. A man who has come to see the weight of his lawlessness toward God knows his immeasurable debt to Christ. Furthermore …

The Gospel is only “Good News” to those who have heard, and believe, that there is a diagnosis of “Bad News” about themselves to start with. If we simply present the Gospel as a route to a better life, we are deceiving people about their true condition. More importantly, we are mis-representing God’s holiness and His serious view of their sin.
“The true ministers of Christ bring men to the law; now this condemns them, and shows them to be under the curse: He that offendeth in one point is guilty of all (James 2:10). As many as are of the works of the law are under the curse; for cursed is every one that continueth not in all things which are written in the book of the law to do them (Gal 3: 10). (William Tiptaft as recorded in “A Sermon preached on 25th December 1829 at the Great Church, Abingdon (St Helen’s)”)
The acknowledged “Prince of Preachers” Charles Spurgeon put it this way:”But more, there is war between you and God’s Law. The Ten Commandments are against you . . . . The First one comes forward and says, ‘Let him be cursed, for he denies me. He has another god besides me; his god is his belly, he yields homage to his lust.’ All the Ten Commandments, like ten great pieces of cannon, are pointed at you today, for you have broken all God’s statutes, and lived in the daily neglect of all His commands. Soul! You will find it a hard thing to go to war with the Law. When the Law came in peace, [Mount] Sinai was altogether on a smoke, and even Moses said, ‘I do exceedingly fear and quake.’ What will you do when the Law comes in terror, when the trumpet of the archangel shall tear you from your grave, when the eyes of God shall burn their way into your guilty soul, when the great books shall be opened, and all your sin and shame shall be published? Can you stand against an angry Law in that day?”
Charles Spurgeon states elsewhere “Lower the law and you dim the light by which man perceives his guilt; this is a very serious loss to the sinner rather than a gain; for it lessens the likelihood of his conviction and conversion. I say you have deprived the gospel of its ablest auxiliary [its most powerful weapon] when you have set aside the Law. You have taken away from it the schoolmaster that is to bring men to Christ.”
Excerpt from What is the Gospel?