Acts 20:27 (NKJV)
If you asked a child what they wanted to eat, they might say that they want something like ice cream. In fact, some children would have ice cream for every meal of the day, if they were allowed to have it, and some adults would too. But most people know that you can't just eat ice cream for every meal, you have to have a proper, balanced diet that includes a variety of things. If you only ate ice cream, but no vegetables or fruits, it would not be long before you became weak and sick because of your unhealthy diet.
If you asked Christians what they want to hear about in a church service, they might give you some answers based on what sounds interesting or exciting to them. But while those topics may be popular, they may not be very beneficial to someone living a godly life. This is like the child with the ice cream, we sometimes naturally and spiritually want things that seem more enjoyable to us, instead of the things that are needed. Just like we need to eat our vegetables naturally, we need to have a good spiritual diet of the whole Word of God that will help us grow and develop spiritually.
In Acts 20, Paul talked about how he taught "the whole counsel of God"; Paul was careful to be sure that his teaching covered all of the Gospel and not just the parts that people considered to be exciting. Too often teaching and preaching is about things people want to hear that seem to excite them, but those things don't necessarily help people to grow and develop spiritually. We need to be sure that we are feeding ourselves with the whole counsel of God and not just with spiritual ice cream.