Sunday Message Recap: Faith and Authority

I, Marty, did not spend much time on the harshest and scariest part of the Matt. 8:5-13 passage on Sunday. It is the consequences of non-faith that Jesus tells the crowd hanging around him. He says that some who think they are going to be enjoying the feast at the end of time along with Abraham, Isaac, and Jacob will be thrown out of that gathering into outer darkness. Why?