Can a saved person lose their salvation?

 Can a saved person lose their salvation? This Question is to me is a very important Question, because it speaks to one's eternal position! I have discovered that many professing Christians truly believe they can lose their eternal salvation. This is troublesome to me, not because i believe i can lose my salvation (I KNOW BETTER!), but because so many are unsure of their own salvation. It makes me wonder if such people truly born-again! Anyhow, if you have a thought you'd like to share on the subject feel free to speak your mind!!!