I am a born-again Christian. I know this. But a while back ( and even now occasionally) I had serious doubts. There was a point where I was devoid of faith and it seemed like all was lost. I wanted to believe, but I just couldn’t. I read the bible, and it would help, but then I’d get a sense of hopelessness and belief would become impossible again. It came to a point where I asked for signs that He was real and He delivered in the form of an unknown call on my phone shortly after I had asked. then, a text saying Jesus never fails, and finally, out of the blue a friend texted me cause she felt like something was wrong. I’ve read that once you were saved nothing could change it, but what about you? What if you decide that you don’t believe anymore? Can you come back? The prodigal son explains that the son comes to his senses and begs his father but the son never forgot the father.
There are several verses that answer your question in no uncertain terms. John 6:39 says it’s God’s will that Jesus will lose none of all those who are given to Him. 2 Cor. 1:21-22 says that God has accepted responsibility for keeping us saved. He’s the one who makes us stand. He put His seal of ownership on us and His Spirit in us as a guarantee.
Remember how clearly Jesus used the analogy of the sheep and the shepherd in referring to His relationship with us? Sheep are prone to wandering, but when they do it’s the shepherd’s job to bring them back. John 10:27-30 explains this very well. No one can take you away from Him, not even you. Romans 8:38-39 says that nothing in all of creation can separate you from His love. That also includes you.