Berkhof writes: “The law comprises everything in Scripture which is a revelation of God’s will in the form of command or prohibition, while the gospel embraces everything, whether it be in the Old Testament or the New, that pertains to the work of reconciliation and that proclaims the seeking and redeeming love of God in Christ Jesus.”
Horton adds: “By means of this two-edged sword, both death and life proceed. through the preaching of the law, the Holy Spirit slays us, leaving us utterly destitute and helpless to save ourselves, and through the preaching of the gospel, he raises us up and seats us with Christ in heavenly places.”
He appeals to 2 Corinthians 3:6 for support: for the letter kills, but the Spirit gives life. “Both are needed,” Horton adds, “so that we lose confidence in our own resources and throw ourselves wholly on Jesus Christ as ‘our righteousness, holiness and redemption.'”
Therefore both the Law and the Gospel are necessary in preaching. You cannot have true preaching without both and this is much of the problem with modern preaching. The modern pastor either only preaches the gospel, God’s love and grace, at the expense of the Law. Or they only preach the Law showing God’s holiness, at the expense of the Gospel. Yet, both must be proclaimed.
Unfortunately in our society today, it seems to be the former brand of preaching that is taking place. The modern preacher seems to want only to talk about God’s love and how much God loves us. This is not a true picture of the gospel because one can come away with the idea that of course God loves me. I’m so great! God’s love is belittled and abused when the Law is not present because His love is only truly understood when it stands in contrast to the Law, which condemn us. There is no real appreciationg for God’s grace, when we fail to see our true need in Christ. Amazing Grace then becomes nothing more than a moving and emotional song, and not something to be amazed about.
But when we see our depravity, by the use of the Law, we see how far we have fallen from the perfect righteousness required by God. We see that we cannot measure up to His perfection, and we need help. In fact, we need perfection even when we see our imperfection, and the moment that we see our imperfection is the moment we see we are helpless. Perfect does not allow for us to start over at the moment of this discovery. Perfect requires perfection from the moment of our conception until death. All it takes for perfection to be missed is one blemish, one sin, one pecadillo to ruin it. The moment we have sinned, or have a sinful heart with sinful desires, is the moment we have missed out on being perfect. The Law shows us this, and condemns us.
The Gospel shows us Christ. He was perfect and without sin. He is the only One that has lived the perfect life. By believing in Him alone for salvation, then we are imputed with His perfect righteousness. Not because of anything found in us, but because of God’s grace alone. When we see all this in the context of the Law, then we begin to see how amazing grace truly is. We appreciate grace for what it is. God had every right to send all of us to hell, but in His good pleasure, He decided to save some. Not because of anything found in them, but becuse of His love and mercy. He showed them the gospel, moved in them, and they believed in Christ for salvation. God uses His word to bring this about, both the Law and the Gospel. Without both, then we are never truly convicted of our sins, and never truly saved. Without repentance, their can be no salvation. Faith and repentance go hand in hand, they are two sides of the same coin. You must have both. One leads to the other. If the other never arrives, then do we truly have the one?
For the pastor to be faithful, he must preach both Law AND Gospel.