Apostolic: Jesus spent three years teaching, performing miracles, and gathering followers.  Among those followers were twelve unique individuals called the Apostles.  They were called by Jesus to spend extra time with Him, to gain deep insights into His teachings, and then go forth to the ends of the Earth to proclaim the Gospel.  In John 20:21, Jesus says to His Apostles after the resurrection:

As the Father sent me, so now I send you.  And when He had said this He breathed on them and said, “Receive the Holy Spirit…” 

This begins the apostolic mission of the Church.  Jesus was sent to bring the Good News to all.  And now He was entrusting this very mission of His to the Apostles.  It was now their responsibility to carry this mission out as unique members of the Church acting in the very Person of Christ the Head.  

“Apostolic succession” is a term we often use to explain that these twelve Apostles then went and spread the Gospel and passed on this unique mission of being Christ the Head to other Apostles.  This continues on until today in the persons of our bishops.  Every bishop alive today could technically trace their line of ordination back to the Apostles and to this one moment where Jesus bestowed his grace on the Apostles by breathing the Holy Spirit on them.  Priests also share in this mission in a unique way in that they are called to cooperate with the bishop in his ministry.

To be apostolic, the Church must also seek to spread the Gospel to all peoples.  This can refer to parents teaching their children how to pray and how to get holy.  It can refer to the task of bringing the Gospel into the workplace and society.  It can refer to the work of missionaries going abroad sharing the Gospel with those who do not know Christ.  The apostolate is a sharing in the one mission of Christ.  The mission that the Father sent Him to do.  And it is the mission that He, in turn, passed on to the Church.  We all share in this mission, so let’s get to work!