Why is the rapture so hard for people to understand?

Les explains that this revelation is something totally different, yet part of the same complex revelation, and it is never referred to anywhere else in Scripture. That is why people have such a hard time contemplating it even today. He notes it is a Pauline doctrine not found elsewhere in the Bible, called a mystery in 1 Corinthians 15:51. The mystery is that one group of believers will not die physically but will be alive when everything comes to a culmination. Nowhere else is this hinted at in Scripture. At the end of the church age, a group of believers will suddenly go from here to there in a split second. Les says it is hard to comprehend; no wonder the unbeliever scoffs, because it takes faith to believe Christ will leave glory, come to the atmosphere, the trumpet will sound, the archangel will shout, the dead believers of the church age will be raised and resurrected, going up to meet the Lord in the air, and then those still alive and remain follow in a split second.