Samuel Brown, in his book First Principles and Ordinances argues that it is through baptism and the temple that we join the "family" of the church. We are adopted into a group of others that similarly have accepted this adoption. An important attribute of this adoption is our ability to empathize with one another.
Adam Miller in much of his writing also addresses this topic through the use and understanding of Grace. He explains that his understanding to God is through his exposure to the grace of interacting with other people. In other words, he understands many aspects of God, and in turn, the gospel through his interactions with others. He further understands the atonement through our connections with one another. In his book Rube Goldberg Machines he writes that the effects of the atonement are such that all must eventually receive of its blessings.
This idea of each coming back to the fold of God through grace is beautifully illustrated through Steven L. Peck's novella A Short Stay in Hell where, while the stay (in our human understanding) is long . . . very long it is only a method to allow those of an incorrect faith to enter into heaven eventually. A major part of this novella centers around the loneliness and need for human connection (and a severe lack thereof) in this hell. More specifically, this connection is needed in order to endure great suffering.
Michael Austin, in his book Re-reading Job also points this out in the way that Job's companions treat him in his suffering, suggesting the question, are we treating those that suffer as if they are a problem in need of fixing, or as humans in need of love and companionship. One of the most moving parts in Job is a small line where his companions simply sit with him, silently enduring (to some extent) his pain. They do not speak with him but share the experience. They empathize with his suffering.
Through these readings and many, many others I have come to understand that life is not a test. At least, not in the traditional Sunday-school view. Rather, life, or mortality is a necessary means to understand and experience suffering, but not only suffering, but learn how to empathize with others through that suffering. Through mortality we gain a perspective of our inevitable death, we experience events in our lives through that perspective, tainting our understanding of suffering with death as a backdrop. And it is through empathy with one another that we gain a oneness. It is through empathy that we can best understand Jesus's atonement as he empathizes with us. As Adam Miller pointed out beautifully in his Romans translation, Grace Is Not God's Backup Plan, we receive grace from God for free; it is through our obedience that we show him our gratitude of that grace. It is this obedience that we display that leads to empathetic thoughts and actions as we become a part of the body of Christ, showing our understanding of what we do affects others as well as our selves in positive and negative aspects.
Life, therefore, is not a test as much as it is a class in which we learn through interactive involvement how to be better versions of our selves, and help others through our own learning to be better versions of themselves.