“Although by this time you ought to be teachers, you need someone to teach you the basic principles of God’s revelation again.” (Hebrews 5:12a)
At this point in the book, the author wants to go deeper but is frustrated that the congregation is not interested or able to. They’ve known about Jesus long enough that they should understand Him well and live accordingly. But evidently they’ve been content to get by with the bare minimum – just enough to keep God content (1 Cor 3:1-3). They don’t spend enough time with the Scriptures to recognize the connections between the people’s prayers, the Prophets’ messages, stories of how God worked with their ancestors, and Jesus’ involvement in all of that (Lk 24:25-27). They can’t handle a complex theological discussion because they haven’t spent time seriously considering the fundamentals of the Faith. They don’t critique their beliefs and teachings from others, so they don’t realize when they’re being gullible and deceived (Col 2:8). They make simplistic assumptions without discernment for particular situations and wise counsel (Eph 5:17).
These Christians might as well be eating the spiritual equivalent of pizza & beer every day. It’s one thing to eat that way as a teenager, but it’s not sustainable for adults. Sure, it’s easy and will keep you alive, but it won’t fuel you through a gym session or the workday or running after the kids all weekend. Part of being an adult involves taking care of others, so it’s pretty bad if you don’t even take care of yourself.
There are also spiritual parallels to the natural stages of growth as well as seasons of productivity and rest. If you’re a new Christian, it’s okay to focus on the core of the Gospel and begin recognizing God’s involvement in your life and the bigger world (Jn 3:16-18). If you’ve been following Jesus for a while, dive deep in Bible study, make a point to learn more about the rest of the Church, and help out with a local ministry (Phil 1:9). If you’ve been a Christian for years, seriously assess your life according to Jesus, move further from warming the pew and closer toward mentoring the next generation of young Christians (1 Cor 13:11, 2 Tim 4:5). If you’re burnt out or you’ve been burned by other Christians, it’s okay to go back to the basics and remember why you started following Jesus in the first place (Mt 11:28-30). The beauty of being part of the Church (the ‘ohana of Jesus) is that we can each serve different needs, and when one needs rest then others can pick up the slack (1 Cor 12:1-31). But over time, we should model Jesus, who was God but still matured mentally, physically, and relationally (Lk 2:52).