How do you know he’s “the one”

I got out of a horrible divorce and I’m actually still going through it where he was a narcissist and emotionally and physically abusive and very controlling. My new man keeps proposing and I am terrified. I want to marry him but I am so scared. How do you know that he’s the one? I thought my first marriage was the one because I grew up thinking that you would work out your problems not just walk away and I can’t go through another divorce. My ex lies so much about me and about who and how I act and I just am terrified that my new fiancé will change. My ex-husband was perfect in the beginning and changed. Kept changing and changing and changing until he had full control over me and was horrible.