Salvation

I can't really remember the context of the conversation, but today someone told me that they get saved everytime they set foot on a plane just in case. I grew up believing that it was possible for people to fall away from salvation. In college I had conversations with students from a Baptist college who believed that once you were saved, you couldn't lose your salvation. They argued that those who "fell away" from the Lord really weren't saved to begin with. In fact, just a few months ago, I had this same conversation with someone at a Bible study and began to doubt what I grew up believing. I have no idea what I believe anymore. It seems as though there are Scriptures that could validate both sides of the argument. Can people really lose their salvation? Can someone who has truly experienced the love of Christ walk away from Him? Does God ever say enough is enough? What about the verses where God says, "I will not contend with you forever."? Has salvation been so severely watered down by Western Christianity that we don't fully grasp the implications of what it means to be saved? The verse that really scares me is somewhere in Matthew 7 where Jesus tells the people who have prophesied and cast out demons in His name to depart from Him because He never knew them. It blows my mind that people can exercise such power and never know the source. It makes me begin to question whether or not I really know the author of my faith or if I am like those who have a form of godliness but deny its power. Every now and then, when the house is empty and no one has called all day, I begin to wonder if I missed the rapture (even though I don't really believe the church will be raptured before the tribulation, I still get that eerie feeling from time to time). It's funny how one little comment can trigger so many questions! If you have any comments, thoughts, or Scriptures, have at it!