No one ever feels like they are adequate to serve the Lord. Well, most don’t. There are a few, but that’s another story. For the rest of us, when God comes and calls us to become His servant, our natural reaction is to say “Who, me?” And, of course, we really are not able to fully serve the Lord in our own strength. Now God has given us abilities and intelligence, so there is a level of activity that we can accomplish using the gifts that God has given. But to ultimately do what God has called us to do, yes, indeed, we are unable.
So why would God call someone into his service who is not able to do what He asks? God does this in order that he might be “with them” and work through them, even to the point that it will be plainly seen that it is God who has accomplished this deed, and not we ourselves. But all of this requires faith. God promises to give Moses a sign that He is with him in this. But what is the sign? It is that, after they have come out of Egypt they will worship on this mountain that Moses is now standing on. So the sign actually comes after the deed is accomplished. In other words, Moses simply has to trust the Lord for now and afterward he will see that God has been with him. Thus, faith is required.
God has called you to be his servant today in some way or another. He has gifted you and put before you the opportunity. You are not going to be able fully to do what he has called you to do, so you will have to trust that he is with you. But in the end you will see that he has, indeed, been with you, keeping his promise to you in wonderful ways. So serve the Lord today and this week, with gladness, knowing that it is in our service to him that we have fellowship with him!