Jeremiah 1:6-8; 1 Timothy 4:12

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.
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.