One of the most famously known text that speaks of belief is John 3:16.
For God so loved the world that he gave his only begotten son that whosoever believeth in him should not perish, but have everlasting life. I'm sure you've heard a million sermons on this text alone so I will consider you experts. My question is what does it mean to believe? I've heard people say just confess it with your lips that Jesus is Lord, but that seems too easy. Not to say that God doesn't want this experience to be easy for us but even the demoms believe (James 2:19). Your scripturally supported opinions are appreciated. In case you're interested in my opinion....belief is obedience....text to come gotta run but didn't want to lose the thought. God bless.