Luke 2:49 And he said unto them, How is it that ye sought me? wist ye not that I must be about my Father's business?
Jesus was twelve years old when He spoke these words. He went into the temple and began to speak of the things of God. The educated people within were astonished by how much He knew. Jesus wasted no time trying to bring the lost to the truth.
This same business that Jesus was working in has been inherited by us also. After all, God is our father as well. It's the family business. We are called to tell the world the gospel message from the moment we accept it. It doesn't matter how young we are. Christ was a child when He began. Our children can minister to the lost as well. Many of them desire to do it more than adults do.
The thing is, we have been "hired" to do a job, and if God was the kind of boss our worldly bosses are, we would have already been fired. Few of us try to reach the lost and live up to the mandate Christ has given us.
If you have the chance to share the gospel with someone, and you don't, it is essentially your fault they are sent to damnation.