What is the falling away

The definition of falling away is pivotal in the rapture theories being debated by much more capable people than myself in today’s great theological debate on the rapture. Being a lay person I will not elaborate of my believes in this issue but will assume, at least for argument’s sake, that the falling away translation is Apostiasies.  And all three gospels give this time as a beginning of the birth pangs.  As for the pretribulational/posttribulational rapture debate I will leave that decision to the reader since the main focus here is questions to ask yourselves in light of the end day messages. 

I believe differing translations is some of the problem in nailing down the exact meaning in “falling away” After finding that John 16:1 in older translations actually read:
RSV John 16:1 "I have said all this to you to keep you from falling away.

Jesus is addressing a latter day circumstance here also.  In this particular use of the word I found the actual translation was Apostasia, which means revolt or rebellion, the English translation is the word apostasy which means “the renunciation of a religious or political belief or allegiance”. The terms stumbling block and offence are also used in differing translations.  Can we then assume that the falling away are only those who will apostasies’? Another question we should keep close to the surface of thoughts if we are living in those predicted Last Days.