Eternal Security

I am now reading the book "Still Sovereign: Contemporary Perspectives on Election, Foreknowledge, and Grace" edited by Thomas R. Schreiner and Bruce A. Ware. I'm on chapter 6 by Professor Wayne Grudem re: the interpretation of Hebrews 6:4-6 and whether a Christian can lose his/her salvation. Since I became a Christian in 2000 I have believed in eternal security, that is, once saved always saved. Dr. Grudem's exegesis of this difficult passage in Hebrews is staggeringly impressive, and is bolstering my belief in eternal security one hundred fold.