The irony of the mature-immature attitude framework is that Christians who believe in and emphasize the simplicity and clarity of Jesus's gift, the creative reality of God's divine purposes, and the personal "friendship" nature of the divine-human relationship appear to be the "immature"ones, while Christians who bury all of this beneath heaps of rational abstraction appear to be the "mature" ones.
Yet on closer inspection, the clarity of Jesus's gift, the creative reality of God's divine purposes, and the personal "friendship" nature of the divine-human relationship all entail a great deal of hard work, dedication, discipline, and tough choices, all of which stem from love.
In a nutshell, the friendship attitude toward God demands an ultra-high degree of commitment, discernment, and personal responsibility. For example, the need for repentance becomes infinitely more pressing and meaningful if one knows he has betrayed or disappointed a loving friend.
On the flip side, the abstract, rational philo-theological attitude toward God takes a great deal of discipline and hard work to study, learn, and internalize, but once it has been internalized, the real hard work, discipline, and tough choices inherent in being a Christian can be largely avoided and eschewed.
Moreover, this lack of commitment to personal responsibility makes rationalization much more accessible.
After all, it is much easier to withhold repentance from an abstraction than it is from a friend who loves you and whom you claim to love.