I will be with you...
God said to Moses in Exodus 3:12 (NIV) And God said, "I will be with you. And this will be the sign to you that it is I who have sent you…"
The sense of divine call increases another notch when there is a sense of God's stamp of authorisation. For sending will not amount to much if there was no accompanying authorisation. For the person sent to properly represent, they must be given authority to act on behalf of the sender.
In fact the word "send" is the Heb "shalach". From this is derived the Jewish legal concept of "shaliach", who is a legally authorised representative. An old Jewish legal maxim puts it this way, "the-one-whom-a-man-sends is like the man himself."
God never sends without accompanying authorisation. Jesus has sent us into the world to impact it with the Good News and through good works. To make disciples and plant churches. And God backs us up!
Matt 28:18-20 (NIV) 18Then Jesus came to them and said, “All authority in heaven and on earth has been given to me. 19Therefore go and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit, 20and teaching them to obey everything I have commanded you. And surely I am with you always, to the very end of the age.”