April 2018 Gaudete et exsultate (Rejoice and be glad!) an Apostolic Exhortation by Pope Francis promulgated on 3/18/2018. This type of papal communication, an exhortation, is a letter to call the faithful to a deeper contemplation and practice of the Christian life.

I found this letter to be challenging and insightful. The pontiff's stated goal was not high theology:

My modest goal is to re-propose the call to holiness in a practical way for our own time, with all its risks, challenges and opportunities. For the Lord has chosen each one of us "to be holy and blameless before him in love" (Eph 1:4).(no. 2)

Much of the exhortation is a call to holiness using the blueprint of the Sermon on the Mount:A Christian cannot think of his or her mission on earth without seeing it as a path of holiness, for "this is the will of God, your sanctification" (1 Thess 4:3). (no. 19)

This is a good letter for all Christians to read and discuss. Here's the link:
Gaudete et exusultate at the Vatican website