[Elsie]

First of all, Christ was addressing the unsaved in that speech, not Christians, so in that context, your interpretation fails. How could His warning concern faith when His warning was directed to those without faith?

Well; since believers had yet to be even CALLED 'christian', you are TECHNICALLY correct. But since this is part of the Sermon on the Mount, a discerning soul would have figured out that there would be a VAST amount of 'believers' in the crowd; right? Matthew 7:1-2

Judge not, that ye be not judged.
For with what judgment ye judge, ye shall be judged: and with what measure ye mete, it shall be measured to you again.

[Boogieman]

“But since this is part of the Sermon on the Mount, a discerning soul would have figured out that there would be a VAST amount of ‘believers’ in the crowd; right? Matthew 7:1-2”

Well, Jesus was speaking to a multitude, but I don’t see any reason to think most of them were believers. Jesus was performing miracles and people were coming from all around to see him when they heard of this, so I think most of them didn’t know much about His teachings before that. Now there obviously were some believers in the crowd also, but the Sermon reads to me as if it is directed to those who don’t know Christ’s message and are just hearing it.