An excerpt from "Bible.org" entitled, "3. Responding To God's Call (Ex. 3:11-4:17)" by Roger Pascoe, states: "When God calls us He often pushes us out of our comfort zone into new places, new activities, new responsibilities. By nature we shrink back from such radical changes in our lives, preferring instead to stay in familiar places, with familiar activities, and familiar responsibilities. It’s a bit like taking a new job, isn’t it? Those first few weeks can be so threatening, so uncomfortable that we often feel like turning back. But as with Moses, so with us, God never fails to give us all that we need – courage, material resources, wisdom, discernment, vision, helpers, confidence in Him rather than ourselves, and even the words we need to say at just the right time." This article may be viewed at: 3. Responding To God's Call/bible.org
Reference: Romans 9:5