You have been built upon the foundation of the Apostles. Today the Church celebrates Apostles Simon and Jude. As with the other apostles who were not in the ‘kitchen cabinet’ of Jesus, these two appear only nominally in the Gospels. The only information about Simon other than his name is that he might have belonged to the Jewish party of the ‘Zealous of the Law,’ (hence the name Zealot). Jude, also known as Thaddeus, is the disputed author of a short epistle in the New Testament bearing his name. He is the patron saint of those in despair or in hopeless situations. Tradition has it that both preached in Mesopotamia and Persia where they were martyred.
The lack or scarcity of information on these two of the early followers of Jesus has not deterred the Church from honoring their memory. The Church celebrates these two men primarily because they were called by name and responded. Jesus called them to join him in his mission. When they heard the summons, they did not hesitate to leave everything behind in order to be with Jesus. Jesus did not present them with papers proving that this group was legally established. Neither did Jesus present them a detailed information regarding his establishment. All that they got from Jesus was a promise of rejection and persecution (cf. Matthew 10:16-25, 24:9). And they still said yes. If not for anything else, these men are celebrated for taking the risk and plunging themselves into the unknown. It was a risk they took for an outcome that was not to come in their lifetime. Isn’t this what discipleship is all about? We are celebrating them for showing us what being a disciple entails. 
We also celebrate these two men because of what St. Paul is reminding the Ephesians in today’s First Reading: the apostles are the foundation upon which men and women of faith are being built. It is in the apostles that Jesus first planted the seeds of faith that are still germinating even today. By allowing themselves to be sent to the ends of the world, they put to action the demands of the Gospel of laying down one’s life for one’s friends. Because of their saying yes to Jesus, the message of these men still goes out throughout all the earth.