The three types of throughput which mature you, are body, soul, spirit; and, they conflict. Maturation is essentially a process whereby the soul comes to dominate the body, and spiritual maturation is where the spiritual comes to dominate the soul. Hence, the goal is for the spiritual throughput to come to organize and thus maximize the enjoyment of, body and soul throughput. For the three are self-contained 'life' units, and they don't mesh without constantly-monitored, control. So if you don't mature spiritually, your life is miserable, as your soul starts out empty, dominated by your body. What passes for maturation in the human race is therefore essentially, a mammoth matrix of rationales for body desires, all dressed-up in moral, high-sounding words.
So spiritual maturation, only happens if you repetitively and persistently live in God's System during your lifetime (see my God's System video), is like living in your home while it is thoroughly remodeled. Most believers won't bear that much change, and instead opt for the familiar body-defined ideas which the soul is then shackled to; or, they invent soul ideas which are really little more than rationalized body wants. Such believers then enter heaven as spiritual babies, giving rise to the need for societal 'classes' in the eternal state.
For YOU are the fruit, not what you do, Isaiah 53:10 contract.