Once Saved Always Saved

Why do some people think that Once Saved Always Saved while others think that Once Saved is NOT Always Saved? We will show you what the bible reads about this topic, we also going to talk about Forgive and Forgiveness, and Blaspheme Against the Holy Spirit and the consequences.
Salvation prayer:
I accept you, Lord Jesus, as my saviour. I confess that You, Jesus Christ, are in my life. I believe You have risen from the dead. I repent and turn from my wicked ways. You shed Your blood on the cross for my sins. I have been a sinner, and I recognize I can't save myself. Lord Jesus, I trust in you right now to keep me from all hellfire and, above all, take me into your Heavenly Kingdom. Thank you for my salvation, Lord. I want the best I can have from You, in your precious name, Amen.