The developments of human consciousness over the past two thousand years have exposed what are often experienced as some uncomfortable truths about the Christian's ultimate relationship to God.
At the time of Christ, Men did not experiences themselves as fully differentiated individuals - life was (to a significant, often large) extent; experienced as a group-member.
And society was organized in the same way - men were classified by nation, tribe, caste, occupation, family-membership etc. -- and these relationships were mandatory and governed by duties on both sides. Duty was, indeed, a foundational virtue in such societies.
The existentialist feeling, first articulated specifically in the early 21st century by Heidegger, of experiencing oneself as having been "thrown" into this world - without consent; seems to have been almost-entirely absent. Men came to consciousness already belonging "in" the world, in their situation; and accepting the duties thereof.
Duty was necessary (or, at least, expedient) because in a society thus organized; those who shirked their duties were coercively transferring responsibilities onto other Men's shoulders.
The undutiful were parasitizing on the group - and thereby benefitting (perhaps thriving) at the expense of the dutiful.
This leeching behaviour could not be allowed to expand beyond some small size, or else the group would inevitably be destroyed.
In such societies the Christian religion, like other religions, was often treated as a matter of group membership.
In Anglo Saxon or Viking England, when the King became Christian, it was felt to be natural and inevitable that all his subjects underwent mass baptism - and believed. Just as the warrior or peasant was bound to his Lord by bonds of mandatory duty, a duty which he would often embrace as his primary ethic; so he experienced the same kind of relationship with God.
But over the past centuries, Men's minds have changed. Modern Man's consciousness Just Is extremely different.
Men can, and often do, differentiate themselves from whatever group of which they find themselves members - or choose some other group with which to affiliate. Furthermore (especially in The West, but to some degree everywhere); there is little or no sense of duty in such relationships; and little reciprocity felt on either side.
This decline of inner-duty has - in practice - had many deleterious effects; and will probably contribute to the destruction of Western civilization. Yet (as the other side of the same coin) these Western societies only exist and used-to thrive; as a consequence of the same changes in human consciousness away-from the group and towards individuality, that are now destroying them.
But - to understand this ancient mind-set requires that - although we now know that duty and love can be separated (and indeed Just Are separated); for these Men of the past, the two quite naturally went together.
This happened then in much the same way as it does even nowadays for (most) young children in close families: the young child conflates love of parents with duty to parents.
And the mother and father does the same with each child. Thus a loving mother of a baby would say it is her duty to feed and care for the child - but also she wants to do so; and, so long as love is constant, does not need to be coerced by a sense of duty.
A loving mother would be annoyed and insulted if her care for her baby was assumed to be motivated by fear of laws, or a sense of duty to The State.
In other words: love transcends duty.
(And this is the core of the lesson for Christians.)
Love renders duty unnecessary - and indeed reveals duty to be an alien intrusion.
And therein lies the rub! In practice; some mothers do not love their babies; and then her proper care may be imposed from externally - made a matter of enforced duty.
And even the most loving of mothers - someone who has (insofar as this is possible) made as strong a commitment to love their child as she is capable of making - may find that there are times and situations when that love wavers; and then a sense of duty may be needed to 'step-in' temprarily until love resumes.
Yet to place duty as the primary motivator for child-care instead of love - on the basis that in this mortal life love cannot always be relied-upon; is at best (and even when genuinely motivated for children's best interests - which is apparently very seldom to judge by the high rates of child neglect, abuse and exploitation in institutions) a social expedient.
An expedient needed in this mortal life where sin contends with virtue - but far from ideal.
Certainly duty is not the ideal basis for the best child care. We can easily imagine - and probably have experienced - a much better basis: namely love.
And this is why Christians should not - nowadays - discuss God in terms of duty. To the modern consciousness, this gives an utterly false picture of the desired nature of the relationship between God and each Man.
This relationship between God and Man is ideally one of mutual love.
On the side of God it is already one of constant and eternal love; and it is for each Man to choose whether or not he desires to return that love, to make love mutual.
But, the tough truth is that love cannot be coerced; it must be given, over and again, moment-by-moment - and lower values such as duty, obligation, or avoidance of guilt, or expediency - should not be the basis of that love.
And Christians should not urge them either - because that is to devalue our relationship with God.
The same choice comes to all modern adolescents. After natural development (aided by social corruption) takes them to a point of detachment from parents, often a degree of hostility; the adolescents or young adults must choose whether or not to love their mothers and fathers.
While dutiful behaviour can be externally imposed, to some degree, on adolescents and adults; and while they can can be psychologically manipulated by playing-upon negative feelings of duty, guilt etc; we readily recognize that this is ultimately counter-productive.
Unless love is freely given from a positive impulse, from the depths of oneself, and by choice - it is just some kind of expediency - and not Christian.
And yet, at the same time, we recognize that in this mortal world of change, decay, death and evil; we cannot rely on love to be continuously active. We cannot be sure to hold-to eternal commitments in this mortal life.
We may be fooled by cunning evil-propaganda, warped by social pressures that we are too weak to withstand, become diseased, or broken by life... Many adverse possibilities may supervene.
We can decide what we want here-and-now; but only make eternal commitments in and for the life to come after death.
It was part of the gift of Jesus Christ to make this possible. He made it possible for us to choose the ideal of love, and by resurrection to enter a situation where all is regulated by love; because love is eternally mutual among all who dwell therein; and that love is unopposed by sin, by death, or by expediency.
For such reasons, it seems to me that modern Christians should clarify their own understanding of this existential reality of the gratuitousness of love; and also grasp that while love may be our ideal in this mortal world...
Love can be (but can only be) full and everlasting in the resurrected life beyond death: in Heaven.
And that is a world that has transcended duty.