Not only this, but when you take a step back and look at what you're actually arguing for, they don't seem to grasp that they're arguing for a weaker, less powerful, much more ignorant God that does pointless things like save people that will reject Him and go to Hell anyway. I get why they do feel and believe this way, I really do. I came to the same conclusions at first when reading these few verses that do look like they are clearly saying we can fall away and lose salvation. So I get it, I've thought the exact same thing while I was truly born-again saved in truth. The thing is it just never set completely right with me fully and I'd always have to throw a qualifier in when I'd make my case. like "I could never walk away from Him, and don't see how anyone could, but I believe I could choose to walk away if I wanted to.
God wouldn't take my free will after I used it to choose Him would He. God doesn't make me "stuck" in Him does He. It couldn't be that we freely come to Him and are then made slaves of His, not able to choose to walk away if I want to. So I get it. This is a hard subject for us in the modern day especially.
Having been born again I am now connected to God by His Spirit as are ALL in Jesus, and He leads us to all truth, and what He did was show me that I did not choose Him, I was drawn to Him by His power. I did not decide to see my life for what it was in truth and turn away from it, I was granted repentance. I did not then grab my Bible and read the rules so I could now obey God, His Spirit has transformed me in power to shed some of these things overnight and then to His word to guide me to all truth while His power sanctifies me and uses me for His glory.
What I found is that the belief that we can lose the gift that we didn't earn comes from 1 major problem. Far too great a view of the power of men, and far too small a view of the power of God. I also just wanted to add that once God showed me this I found that it doesn't contradict His word at all, that His word wasn't saying two different things, that the closer you get to truth the more it fits the WHOLE of scripture. His word is amazing. I also as an ex-false convert want to add that this argument about losing salvation is much easier to make when you haven't ever experienced His power in truth. A power we may all have come to in different circumstances, but that we who have been born again all know without question. I can't lie that when I here a Christian teach that "we all have doubts", I don't disagree to a degree, but as a Christian I have NO doubt that God is real, I have NO doubt that Jesus is His Son and the ZONLY way to reconciliation with our Creator, and I don't have any doubt that I'm saved and connected to God. None. And I know that has to come across as arrogant like I'm boasting in my certainty, but I didn't make myself certain and I get and want NO credit for it. Jesus gets every single bit of ALL that, because it was the power of my rebirth that opened my eyes to the FACT that God is REAL, Jesus is REAL, that I I was born with a dead spirit that couldn't ever see life outside of Jesus sacrifice and Gods perfect plan. When He resurrected that spirit to life and reconnected it to His, brother that lifted the veil and opened my eyes to something they can no longer be shut to. I may have doubts about how this works here, or how that over there's going to play out, but as far as doubt about God and Jesus being REAL in REAL LIFE. He killed that with the old me. This is also the power they argue that they could walk away from. You can't. ALL God, none us.