What should pastors strive to cultivate in their congregations through their sermons?

Joel Beeke explains in this video that what pastors should strive to communicate to their congregations is to show them the enormity of their sin and the enormity of grace. Satan, the world, and the natural heart do not want this.

Satan desires to both minimize the seriousness of sin and to minimize the necessity of grace. The world similarly attempts to persuade us that our sin “isn’t so bad” or "you can do it once." However, by minimizing the seriousness of sin, they also minimize the grace of God. If sin isn't serious, there is no need to flee to Christ alone.

Thus, a pastor’s goal should be to show people the dreadfulness of sin. Even the smallest of sin deserves hell because God is holy. A pastor also needs to preach that Christ’s sacrifice covers all iniquity and His blood cleanses all.

1 Timothy 1:15 (NKJV) – “This is a faithful saying and worthy of all acceptance, that Christ Jesus came into the world to save sinners, of whom I am chief.” 

So this is a faithful saying, it never fails. And to be accepted of all that Christ Jesus came into the world for this very purpose to save sinners of whom I am chief can you be beyond the chief sinner well John Bunyan actually was a Puritan and he said reason Paul could say I am the chief sinner is because he didn't know John Bunyan yet. Bunyan said, I've got the most wicked heart in all of England, but I have found grace. Amazing grace for an amazing sinner. That's what you want to cultivate in your people.

Show them the enormity, Pastor. Show them the enormity of their sin and show them the enormity of grace That's your work and that's what the world doesn't want that's what Satan doesn't want and That's what a natural heart doesn't want. You know what Satan wants to do? He wants to minimize sin and he wants to minimize grace. Your sin isn't so bad, he says.

And then when you do sin, he says, you can't be saved. You've sinned too much. Comes as a roaring lion, he comes as an angel of light. He's always trying to minimize sin and minimize grace. The world does the same thing.

Now it's, yeah, that's not so bad. You can do that. You can do that once. Some notable sin. And Then they minimize grace because they don't flee to Christ alone.

But when you're a pastor, your goal is to Show people the dreadfulness of sin. Every sin, the smallest sin deserves hell because God is holy and God cannot allow into heaven anything that is stained with sin. You need a savior. But then the beauty is this, the savior covers all inequity, all sin. His blood cleanses from all sin, 1 John 1, verse 9.

So you preach both.