The resurrection of Jesus is the most crucial part of the gospel. Not only was it essential to Jesus' mission, but it authenticates everything else he said and did.
Whether we encounter the gospel of Jesus as children in church or in a presentation from an enthusiastic Christian, we may only absorb a few pieces of the whole thing.
The Apostles' Creed lays out all the basics in a short outline, and is affirmed by almost every Christian church in history.