Why should you believe what Jesus said? That is a very good question. Why should anyone believe anything that Jesus said? I think that this is the question of questions. This is the most important question that you can answer, if in fact, that you can answer it.
We can know that there is a Second Coming because there are many unfulfilled prophecies regarding the Lord’s Coming and because Jesus told us that parable in Luke 19:11-27. So, the question is not of his Coming, but rather the question is when will he come relative to other events in the biblical scenario.