Isaiah 41:10 Fear thou not; for I am with thee: be not dismayed; for I am thy God: I will strengthen thee; yea, I will help thee; yea, I will uphold thee with the right hand of my righteousness.
I think the greatest example in this passage was Christ Jesus, since despite so much conflict and danger, he was never afraid, and this was thanks to the conviction that the Father was with him.
What God wants is to give us the conviction that Christ Jesus had that he is with us, for this reason we should not be afraid even if this means that we are crucified, that is, lose our lives because of him.
So if God has already told you that he is with you, do not fear.