In your opinion what causes christians to believe in Jesus

[Mister Agenda]

It's not clear why John has ignored these two different definitions, or why his arguments use the word trust, that is only found in the primary definition, and doesn't acknowledge the second religious definition of the word at all?

Because definitions are not prescriptive. And it is improper usage of a dictionary to shop around the different senses and give them all equal merit. You are supposed to go and look at the context in which a word is used and be able to infer its meaning. And even if you still care about proper definitions, you need to pull out a Greek concordance and dictionary and research its original usage and meaning, not pull out your merriam-webster.

It isn't shopping around. The word has two different senses. Can you not just state which sense you are talking about? Using them interchangeably is confusing. I recommend the second sense when you're referring to faith in spiritual things and just say 'believe' or 'trust' when you mean the first sense.