Two Unchangeable Things

"Hebrews 6 gives us an anchor for our soul: "So when God desired to show more convincingly to the heirs of the promise the unchangeable character of his purpose, he guaranteed it with an oath, so that by two unchangeable things, in which it is impossible for God to lie, we who have fled for refuge might have strong encouragement to hold fast to the hope set before us." Hebrews 6:17, 18 * Dale asks about the Nephillim. Where they angels? Did they have relations with women? * What is easy believism? Does it have anything to do with Lordship Salvation? * Does God call some people and not others, or is everyone called who has heard the gospel? * Does Revelation 22:18, 19 show that someone can lose their salvation?