Jeremiah 1:8-9
Then the Lord put forth His hand and touched my mouth, and the Lord said to me,
"Behold, I have put My words in your mouth,
See, I have this day set you over the kingdoms,
To root out and pull down,
To destroy and throw down,
To build and to plant."
Jeremiah had his work cut out for him. He was probably between 20 -30 years old. we know this because he calls himself a youth, and males didn't reach the legal age of maturity until they we 30 years old. This means he was probably going to be considered an impertinent and/or rebellious youth - which is not good since he was born into the priesthood.