God likes using amateurs. Look at Moses. He wasn’t an expert at anything when God called him. God said “Hey, I need you to go talk to Pharaoh and free my people,” and Moses said “You have got to be kidding. Me? Talk to Pharaoh? I stutter. Lead everybody out of Egypt? Who would follow me, I’m nobody?” And yet he did, with no training and no expertise.
Look at King David. He was just a boy. He was too small to wear the armor that was given to him when he went up against Goliath. The whole Israelite army hadn’t been able to get past this giant. One boy, armed with the strength of God and a rock, did the job.
Why a rock? Why not a sword’? David used a rock because that is what he knew. He wasn’t a warrior. He was a shepherd. He used a slingshot to chase off the wolves that were terrorizing his sheep. This time, Goliath was the wolf. One hit with one tiny rock, and he was down. God uses us like that. The small stuff becomes the important stuff. The underdog wins.
David didn’t use a sword, he used a stone. He used what he knew. Note that he didn’t even bring the stones with him. He went to a nearby stream and found them. God provides what we need for the task at hand at the time we need it. It isn’t on us to do all the work. It is up to us to show up and let God do the work through us. Just like with Moses, God calls us and uses us as we are.