The main message that was brought was the salvation message. Jesus gave many other messages as well such as on love and forgiveness.
Different churches sometimes focus on different messages, or topics within the Bible. For example Joyce Meyers focuses on Christian Living. Rod Parsley seems to focus on the salvation message and the power of God.
The problem comes when churches start to give messages that are really not supported by the Bible. They added their own interpretation and twist to what is actually being said, and even take scripture out of context of what it actually means.
This is where we need to be careful. Are we getting God's word, or the Pharisees version so to speak. They were notorious for doing this, and this was the reason Jesus fought with them so venomously.
The only way we are going to know if we are actually hearing God's word or man made interpretation of it is to read and study the Bible. Don't let anyone tell you that you need a degree to understand it. Anyone can understand the basic message when reading.
What I like about the Bible is that the more you read, the more you will understand. I don't know how many times I have heard this and actually have it happen to myself, I read this passage dozens of times already and I just saw something new in it. I always believed that the Bible backs itself up. For any message, you should be able to find the same message in several different places.
Be careful of man made traditions and practices. I do believe there are pure unmixed messages, and I also believe there are hidden messages. Be careful with the hidden ones, but they are great when God reveals them to you.