Here, off the top of my head, are some "marks" of what Christian formation should aim at/produce:
- A secure awareness of a relationship with God in Christ, in the company of the Church.
- An ability to verbalize that relationship with confidence and clarity.
- A basic familiarity with the long arc of the narrative of scripture--the series of covenants in the Old Testament (Noah, Abraham, Moses, David, the Exiled Jews), the life of Jesus, the story of the early church in Acts.
- A habit of corporate worship on Sundays and daily private prayer, along with related spiritual disciplines.
- An awareness of vocation--a habit of asking the question, "What is God calling me to do?"
- An awareness of one's spiritual gifts, and a passion for exercising them.
There could be more, but this seems enough of a challenge!