God created us brilliantly and he knows what we can do, sometimes when God asked us to go to the world and preach the gospel we are all confused, thinking about what we are going to say, some of us can't even face three people and we are asked to face the crowd, some of us are asked to face Tyrant or our greatest fear and we become scared but said he will be us.
And he said, Certainly I will be with thee; and this shall be a token unto thee, that I have sent thee: When thou hast brought forth the people out of Egypt, ye shall serve God upon this mountain.
When we are working for God is not because of us, and God will not put us in a situation that we will be alone because he will always be with us and that's what he said in this verse. He will always be with us even though it looks like we can't do it but remember with God everything is possible.
If we look at the story of Moses when God ask him to go and save the people of Israelite from the hand of king Pharaoh, God send a man and not a whole army just a man but what was inside him is greater than anything, he was scared but God was with him throughout the journey and a man defeated king pharaoh and his army.
When we are working for God we must have courage and it is normal to be scared at first but God will not forsake us. The journey might look tough or rough and even sometimes impossible but remember if God is with us nothing can be against us. Be courageous, our God is able.
Thanks for your time.