An angel freed the apostles from jail and told them to teach about "the life" (Acts 5:20, our transl). Christianity is new life, but Christians must be taught to live this life, thus, the great importance of teaching in the Christian life and regarding this life.
On the day Jesus rose from the dead, He spent hours in the afternoon and evening interpreting the Scriptures (Lk 24:27) and opening the apostles' minds to understand the Scriptures (Lk 24:45). At the first Christian Pentecost, Peter was preaching and teaching. Thereupon, the newborn Church "devoted themselves to the apostles' instruction and the communal life, to the breaking of bread and the prayers" (Acts 2:42). After an angel freed the apostles from jail and told them to keep teaching, they devoted themselves to "prayer and the ministry of the word" (Acts 6:4) by resisting temptations to lose their focus on teaching God's word. They even filled Jerusalem with their teaching (Acts 5:28). Jesus was frequently called "Rabbi," meaning "Teacher" (see Jn 20:16), and the Church founded by Jesus is therefore a teaching Church.
In our spiritually anorexic culture of death, we must again desire to be taught and to teach God's word. Otherwise, we will not know how to live the Christian life, and Christianity which is not lived is an aberration. As the Holy Spirit convicted the world of sin (Jn 16:8) and at Pentecost gave the early Church a hunger for God's word, may He, this Easter season, also convict us of sin, crucify us to the world (see Gal 6:14), and give us a baptismal hunger for God's word of life (see 1 Jn 1:1).