The LORD answered Moses, "Is the LORD's arm too short? You will now see whether or not what I say will come true for you."~Numbers 11:23 (NIV)
Is there any doubt He wants me to believe Him? I...you...can believe Him. I want to believe Him because it's our calling as, well, believers.
Jesus replied, This is the work (service) that God asks of you: that you believe in the One Whom He has sent [that you cleave to, trust, rely on, and have faith in His Messenger].~John 6:29 (AMP)
We wear ourselves out doing things for God, assuming that is our work. But Jesus clearly states that our job is to believe. Why is it work? Have you ever believed God for something that you knew couldn't happen in the natural realm? I'm sure you would testify that it can be laborious. Still, it's what we are called to do.
In John 17:4, Jesus prays, I have brought you glory on earth by completing the work you gave me to do. (NIV)
May it be so for us.