The problem of humanity is that we are invited or called to worship God. There is no demand in Jesus Christ to worship Him. It is problematic for us that "this call of God...is to be understood in the light of Jesus Christ, not as a purely categorical imperative or a moral law, but as the call of God to communion with Him the Creator, and through Him to communion with" (pg. 73) the rest of humanity. The invitation to worship God through His Revelation would be much easier for us to accept if it was not a call at all.
If God issued forth a categorical imperative instead of a hypothetical imperative, we would have no choice but to worship. For a categorical imperative is something that we have to do. It is an ontological ought (to continue in the language of Kant), a command that is innate in the core of our being that we have to follow. This would take away our choice, which we would protest, but at the same time, get rid of many difficulties.
God's hypothetical imperative tells us that we should worship Him, not that we have (ought) to worship. The hypotheticalness of it tells us that it is up to us to decide how to answer. It places the responsibility on us, not on God. We would much rather be free of such responsibility than to have it. It is a burden that sometimes feels to heavy for us.
We then, after hearing the call, have to respond. We can respond with a Yes and join in with communion with God (and thus the rest of the created order) OR we can respond with a No and reject community in favor of solitude. ( However, "this Either-Or", this Yes or No, "is not that of divine Creation; it is only as a result of the wrong answer, which is the result of sin, that this "Either-or" confronts us as an alternative." (pg. 73) When the individual answers No, he or she creates the Either-Or situation.Our freedom is not to choose, but it is a freedom to be "in the love God, which fills his whole life." (pg. 73) )
Yet when we answer No to the call, we are not just answering No to God. We are answering No to ourselves. For " the true existence...can only be completed in the answering act of man." (pg. 73) When we deny the invitation to community and choose solitude, we also choose to be incomplete, to have an ontological lack (to use the language of St. Augustine). True human existence is only "existence-in-love" (pg. 73) and when we reject love, we reject true existence and become inauthentic, incomplete. "When man decides against this divine destiny he is in opposition, not only to an ideal destiny, but also to his own nature, and this self-contradiction is now within himself." (pg. 73)
When humanity answers no, there is "a change in man's relation to God; it is the break in communion with God, due to distrust and defiance." (pg. 92) Out of this distrust and defiance, it is revealed that "the fundamental cause for this breach in communion" is humanity's "desire to be "as God". Man wants to be on level with God, and in doing so to become independent of Him." (pg. 92) However, we do not realize the mistake in breaking off relation with God. "Man's divine destiny means being "like God". freedom. Man is intended to be free, to be like God; but now man wants to have both apart from dependence upon God." (pg. 92) We were created to be free, but to be free in community, not in the solitude that we continually create.
"Sin", for Brunner, "is throwing off restraint, denial of responsibility hence emancipation from that which makes us responsible, in whose Word we have both our freedom and our bondage. Sin is the desire for the autonom of man, therefore, in the last resort, it is the denial of God and self-deification; it is getting rid of the Lord God, and the proclamation of self-sovereignty." (pg. 93)
This has been the Modern philosophical project, to assert that Man is autonomous, a law unto itself, and that we can throw off the shackles of anything that limits us. The desire to be autonomous is the desire to be God.