Apostle is the one who preaches that Jesus is Lord. He gives such a testimony because strongly believes and trusts in his heart. In addition, he knows that all the peoples can be saved by the divine grace.
The disciple of Christ teaches his sisters and brothers that they should believe with their heart and be justified. They also need to confess their faith and acknowledge their weaknesses.
The follower of Jesus reads the Scripture carefully and understands the will of God. Thus, he can easily recognize what is good and what is evil. Moreover, he listens to his conscience during the silent prayer and meets with the Lord is the Spirit.
Thanks to the Holy Spirit he is enriched with many gifts and charisms. Furthermore, he receives the divine power to call on the name of the Lord in the world. Accordingly, he is a missionary who brings the good news to all the peoples. He never gives up but continues to share the gospel. In this way, his voice goes forth to all the earth and to the ends of the world.