Jeremiah 1:4-10 (NIV)
4 The word of the Lord came to me, saying,
5 “Before I formed you in the womb I knew[a] you,
before you were born I set you apart;
I appointed you as a prophet to the nations.”
6 “Alas, Sovereign Lord,” I said, “I do not know how to speak; I am too young.”
7 But the Lord said to me, “Do not say, ‘I am too young.’ You must go to everyone I send you to and say whatever I command you. 8 Do not be afraid of them, for I am with you and will rescue you,” declares the Lord.
9 Then the Lord reached out his hand and touched my mouth and said to me, “I have put my words in your mouth. 10 See, today I appoint you over nations and kingdoms to uproot and tear down, to destroy and overthrow, to build and to plant.”
1 Timothy 4:12
12 Don’t let anyone look down on you because you are young, but set an example for the believers in speech, in conduct, in love, in faith and in purity.