The gospel is a simple truth that Jesus died for the sins of the world so that whoever believes in him shall not perish, but have eternal life. Add anything to that - no matter how wise or religious it may sound - and it is no gospel; no good news. We cannot add anything to what Jesus has done for us. We must not add anything to what Jesus has done to save us. We need not add anything to what Jesus has done for us. Just believe. Just trust. Just rejoice. Just live. That may be astonishing in a good sort of way. But it's true.