Now the word of the LORD came to me saying, “Before I formed you in the womb I knew you, and before you were born I consecrated you; I appointed you a prophet to the nations.” Then I said, “Ah, Lord GOD! Behold, I do not know how to speak, for I am only a youth.” But the LORD said to me, “Do not say, ‘I am only a youth’; for to all to whom I send you you shall go, and whatever I command you you shall speak. Be not afraid of them, for I am with you to deliver you, says the LORD.”
–Jeremiah 1:4-8