Rom. 10:13-15 shows how a person is saved in reverse order. Verse 15 says that the preacher is sent to bring glad tidings which is the Word of God. Verse 14 says that when people hear this gospel, they believe. Once they believe, they call on the name of the Lord. Verse 13 says that when they call on the name of the Lord, they will be saved.Belief isn't a decision. You either believe or you don't.
Faith itself comes by hearing, and hearing by the word of God. Many here believe that verse says faith comes by hearing the word of God. But that isn't what the scripture says. It says faith comes by hearing, and hearing by the word of God.
Note:
Doesn't say: hearing the word of God produces faith.
Does say: the word of produces hearing. Hearing produces faith.
This is the power of the gospel that Paul was not ashamed of.