The word is very clear that we can walk away from Jesus and as we walk away from Jesus we walk away from our savior and as we walk away from our savior we walk away from our salvation and once we walk away from our salvation and don't go back then we will lose it. Very clear this is everywhere in the word, you have to be a dummy not to see it, the whole Epistle of Hebrews is actually named by many scholars the Epistle of warnings. And of course if you're Cessationist or a calvinist of course all of this will be considered as a heresy but you are actually the Heretics. Salvation is a gift but even in the -natural somebody gives you a gift you can do whatever you want with it, you can take it and throw it away later on or you can reject it. Freely given as well as freely thrown away based upon your free moral agency.Shalom