The devil, as a roaring lion, walketh about, seeking whom he may devour. —1 Peter 5:8
Notice the scripture says "may" and not "will." In other words, you have something to do with whether he is able to devour you. And if you know anything about Satan, he doesn't have any power. The only power he has is the power you give him.
Fear, of course, is one of his favorite tactics, so he will try to use fear to stop you. But don't give in to him. Go ahead and do it afraid. When God tells you to give somebody a tract or witness to a person, say, "Yes, Lord, I want to do what You're telling me to do. I feel kind of afraid, Lord, but I believe You're with me, so I'm just going to do it."
When God tells you to give an extra big offering in church because He wants you to plant it as a seed (See Luke 6:38) so that you can come up higher in your finances, say, "Okay, Lord, I'll do it. I know that means I will have to really trust You for some provision, but because I believe I'm hearing from You, I'll do it."
Don't let the devil rob you of the destiny God has for you. Step out and face your fears; face your pain. You can be a victorious Christian, or you can be one who is never quite able to enjoy the fullness of God. The only difference between the two is that one is stopped by fear and the other does it afraid. Determine today to do it afraid!