Isaiah 48:15 I, even I, have spoken; yes, I have called him. I will bring him, and he will succeed in his mission.
God calls people to do things because He knows they can do things! He does not call people to test how much they can do or how far they can go – that's just how we feel.
Our feelings are just that – feelings. God knows the truth and knows what we are capable of. If we continue to walk with Him and trust Him for guidance, we will see how much we can do.
Alone, we are just that; alone. But with God we can do so much more and reach so much further.
Trust Him, always.