Some pastors do not know how to preach the Gospel. They have confused motivational speaking and music with the power of God’s word. So here is a brief summary of what the preaching of the Gospel is.
The sum of the preaching of the Gospel is this:
• to convict of sin;
• to offer for Christ’s sake the forgiveness of sins and righteousness, the Holy Spirit, and eternal life;
• and that as reborn people we should do good works.
So Christ includes the sum of the Gospel when He says, “Repentance and forgiveness of sins should be proclaimed in His name to all nations” (Luke 24:47).
— Book of Concord: “Apology of the Augsburg Confession,”
Article XIIA (V). Repentance, 29.
This is why Paul resolved to know nothing in Church “except Jesus Christ and him crucified.” The Gospel was not preached “in plausible words of wisdom, but in demonstration of the Spirit and of power, so that … faith might not rest in the wisdom of men but in the power of God.” (1 Corinthians 2:2-5, ESV).