"He that overcometh, the same shall be clothed in white raiment; and I will not blot out his name out of the book of life, but I will confess his name before my Father, and before his angels. " (Revelation 3:5)
So we can lose our salvation, can't we? Well, first off in this verse Jesus makes a promise. He says "will not blot out", not "might not blot out". It is a PROMISE to EVERYBODY that overcomes. Of course, those who do not overcome will be blot out. But who are the overcomers?
"For whatsoever is born of God overcometh the world: and this is the victory that overcometh the world, even our faith. " (1 John 5:4)
If you are born again, you are an overcomer!
And who is in the Book of Life? When do you get included in there? When you get saved, correct? Well, let's see...
"Thine eyes did see my substance, yet being unperfect; and in thy book all my members were written, which in continuance were fashioned, when as yet there was none of them. " (Psalm 139:16)
So we all were written there before the foundation of the world. God bless