There are two components preached on in every sermon; You Do and Christ Do. The You Do can be preached as I Do, We Do, or You Do, but they are all effectively the same thing. For the purposes of this post, I will only refer to it as You Do. Whether a sermon is good or bad is dependent on how each Do is used.
The bad sermon will say that you need to do X for God. It will say that we are doing Y for Kingdom. It say that I have done Z for Jesus. You can hear a lot of this in pop “Christian” music. Sure, Jesus gets mentioned seventy-seven times in four minutes and thirteen seconds, but lyrics are strangely me focused. On the same token, Jesus is often bound and gagged, relegated to a cameo guest appearance with no lines. At most they make mention that Jesus died for your sins and then brings it back to what you need to do because of it.
The good sermon, however, puts the You Do squarely in the negative. What You Do is sin and there is nothing that You Do that can ever redeem you. But the Christ Do of the sermon is glorious. Christ lived a sinless life. Christ took your sins, the You Do, upon himself. Christ died and suffered. Christ absolved the You Do.
The You Do is tainted in sin, even when You Do good. The Christ Do forgiveness, mercy, and absolution. And there is nothing that You Do which is a good apart from what Christ Do.