You may plan to go on a picnic on a certain day, but can you be sure you will be able to do what you plan? What could happen to prevent you from going on that picnic? It could rain. You could get sick. You could get a flat tire...
Many things could happen to keep us from accomplishing what we plan to do. But nothing could ever stop what God determined. The weather can’t stop Him because He controls the weather. Weakness can’t stop God because God is all-powerful. Lack of sufficient resources can’t stop God because He has unlimited resources. God has no limitations and controls all things.