What did Jesus mean? What was He telling us when He said, "For many are called, but few chosen."?

If you, as a Christian man have learned anything from the misuse of "Judge not, that ye may not be judged," Matthew 7:1 and "Lord, behold, here are two swords." And He said unto them, "It is enough". You should have learned that one of the most important keys to understanding Scripture is Context, Context, Context. For looking at "For many are called, but few chosen." all alone is not going to give you context, it is instead going to either leave you wondering, confused, or gullible to an interpretation done by some who puts filthy lucre ahead of your soul.