Understanding #1

Ok, so I had this idea today while I was reading Matthew 5:17-20. Why did I think about a blog in the middle of my studying? Well, for the second day in a row, I was stumped trying to understand a piece of Scripture. I just couldn't wrap my head around it. So I got this idea that maybe some of you could help me get it. So here's how this is going to happen. I will give you the scripture and what I thought about it. Then hopefully, you can help me understand God's meaning about it. This should be fun. Oh, and don't hold back anything, please. Here we go...

So yesterday I read Matthew 5:13-16. I read this before church Sunday morning, which meant I was reading it at 6 o'clock in the morning, and I was stuck on it all day. I had a hard time focusing on what Tyler was saying in his message. So here is the verse that got me.

Matthew 5:13
"You are the salt of the earth. But if the salt loses it's saltines, how can it be made salty again? It is no longer good for anything, except to be thrown out and trampled by men."

Now, I get the part about us being the salt. But what I don't get is the part that's italicized and colored part. I don't get the salt being thrown out and trampled by men. I can't help but get stuck on the thought, "Is this talking about being thrown out of the Kingdom of Heaven?" I am not a believer at all in "unforgivable sin" or "losing your salvation." But at the same time, this verse is directly talking about the salt losing the saltiness. I know the salt is supposed to mean believers, so is saltiness supposed to mean beliefs? It seems like that fits right?

Salvation is an issue of the heart, I totally get that, so God only calls people believers if they are actually believers. He never says someone is a believer if he knows they don't believe. Makes sense. So I would imagine that God wouldn't call something salt unless it was really salt. So this leads me to believe this verse is talking about a Christian who has fallen away from God, what we sometimes call "back-slidden." I just can't help but keep thinking this verse is saying that if a Christian has fallen away from God, that person will be thrown out of the Kingdom of Heaven. But at the same time I don't believe God does that.

Can someone please lend some thought to this issue of being thrown out of the Kingdom of Heaven?