Don't be so sure.
C.S. Lewis said when you give yourself to God, He gives you back to yourself, only better.
Stop reading Narnia and pay attention. You give yourself to God, you give up individuality and reason. You may believe that enslaving yourself to a confused iron-age religious tract may make you "better," but it leaves you less of a person.
And the word is not the same, unless you want to challenge every English lexicographer on it.
I'd be happy to. Its the same word, from the same etymological origins, with slightly different connotations depending on use.
Stop reading Ayn Rand and read Aristotle instead. Then you can move on to Aquinas.