Joh 6:40 This is my Father's will: That everyone who sees the Son and believes in him should have eternal life, and I will raise him to life on the last day."
The demons believe He is who He said He is, they knew it for a fact. They know and believe He was raised on the third day. They know what is going to happen, just as He said it will - (did you come to torment us before the time?)
If you believe Him, you will do one of two things:
1. You will do all He said or,
2. You will see that you don't and will ask for the help you need.
Aren't we constantly doing these two things as He shows us what our heart is up to in matters? Who hasn't struggled with belief? Who hasn't examined the storing of treasure on earth against all He told us? Who hasn't had their life fall apart or implode at some point and asked, where ARE You, Lord??
Is believing simple? There are a lot of hindrances (the world and our own self for two) to the obedience of faith. Try not storing treasure on earth and wait to hear your own family calling you a fool and the entire world siding with them. Then wait and hear the Christians you know saying you're a fool too!