For most Christians, officially, Omni-God is mandatory - free will/ agency... not really

The problem for traditional, orthodox mainstream Christian Churches is that they make a very Big Thing about the creator deity being Omni-God - but when it comes to the free will of Men... Well, freedom is accorded much, much less significance. 

On the one hand; Omni-God is absolutely mandatory - the church member must swear to that concept. 

On the other hand; each Man's freedom... well, it is supposed to be present and effective. Christians are supposed to be able to choose our values, commitments, behaviours - either because we get divinely evaluated on them, or else simply because these decisions have consequences related to salvation. 

However; both in theory and in practice, freedom may be (more, or less) dispensed-with by this type of Christianity. At the very least least, Man's freedom gets so hedged-about with so many caveats, that when it comes to the crunch - e.g. when it comes to a conflict between Man's Freedom and God's Omni-status... well, agency means little or nothing. 

Omni-God Must Be - but Man's Freedom is something rather difficult, something we are allowed to doubt and debate... 

In the crunch, Omni-God prevails and freedom is imprisoned, and perhaps forgotten. 

Looking at a couple of Protestant documents: The Thirty-Nine Articles of 1571 are (in theory, if not in practice) the confession of the Church of England, and all the other churches in the Anglican communion - third largest in the world. This has as its first item of faith, the Omni-God:

There is but one living and true God, everlasting, without body, parts, or passions; of infinite power, wisdom, and goodness; the Maker, and Preserver of all things both visible and invisible.

The Westminster Confession of Faith from 1646 is the basis for several nonconformist groups, including the Presbyterians. This is more explicit, and hard-line, in its Omni-Goddism than the 39 Articles; and requires affirmation of a conception of the God that would (of itself) probably satisfy the most ardent pure-monotheist: 

There is but one only living and true God, who is infinite in being and perfection, a most pure spirit, invisible, without body, parts, or passions, immutable, immense, eternal, incomprehensible, almighty, most wise, most holy, most free, most absolute, working all things according to the counsel of His own immutable and most righteous will, for His own glory, most loving, gracious, merciful, long-suffering, abundant in goodness and truth, forgiving iniquity, transgression, and sin; the rewarder of them that diligently seek Him; and withal most just and terrible in His judgments; hating all sin; and who will by no means clear the guilty. God hath all life, glory, goodness, blessedness, in and of Himself; and is alone in and unto Himself all-sufficient, not standing in need of any creatures which He hath made, nor deriving any glory from them, but only manifesting His own glory in, by, unto, and upon them; He is the alone foundation of all being, of whom, through whom, and to whom, are all things; and hath most sovereign dominion over them, to do by them, for them, or upon them, whatsoever Himself pleaseth. In His sight all things are open and manifest; His knowledge is infinite, infallible, and independent upon the creature; so as nothing is to Him contingent or uncertain. He is most holy in all His counsels, in all His works, and in all His commands. To Him is due from angels and men, and every other creature, whatsoever worship, service, or obedience He is pleased to require of them.

Having established the absolute requirement of belief in an Omni-God - what do these documents say of Man's freedom?  

39 Articles: The condition of Man after the fall of Adam is such, that he cannot turn and prepare himself, by his own natural strength and good works, to faith; and calling upon God. Wherefore we have no power to do good works pleasant and acceptable to God, without the grace of God by Christ preventing us, that we may have a good will, and working with us, when we have that good will.

Westminster: Man, by his fall into a state of sin, hath wholly lost all ability of will to any spiritual good accompanying salvation; so as a natural man, being altogether averse from that good, and dead in sin, is not able, by his own strength, to convert himself, or to prepare himself thereunto. When God converts a sinner and translates Him into the state of grace, He freeth him from his natural bondage under sin, and, by His grace alone, enables him freely to will and to do that which is spiritually good; yet so as that, by reason of his remaining corruption, he doth not perfectly, nor only, will that which is good, but doth also will that which is evil. The will of man is made perfectly and immutably free to good alone, in the state of glory only.

We see that, in contrast to the much-emphasized and freedom of God elsewhere described in these documents; in this earthly mortal life, Man is characterized mainly by un-freedom. 

Man is describing here as lacking the freedom in the divine sense - that freedom which is necessary for creation, and indeed (I would say) for love. 

In these confessions; Man cannot will good, but can only will a kind of double negation of rejecting evil, or will acquiescing to the good that is done-for-us and given-us by God the Father and Jesus Christ. 

What I see; is how far from the situation described in the Gospels, especially the Fourth Gospel (John) Christianity had developed by the time of these confessions. How close Christianity had come to the pure monotheism of Judaism or Islam; by which Man's freedom is (so it seems to me) almost solely related to the choice of obedience and submission to God's will, law, and commandments. 

Even this minimal version of human agency as obedience is, by my understanding, impossible when God is truly Omni. 

When God is everything necessary, Man's existence and "choices" mean nothing of real value.

When God is absolute and infinite in knowledge, power, and presence; this eliminates any need, space, or place for Man's agency to exist - so it gets ignored.

For orthodox, mainstream, traditional Christian Churches; the Omni-God is absolute, compulsory, officially-required, built-in. 

Human free agency - by contrast - is treated like an optional extra, a mere embellishment or decoration on the rock of faith; nice but (when the chips are down) not-really-necessary.   

Therefore; if a Christian believes in the reality and vital importance of his own free agency to salvation and theosis - to living this earthly mortal life...

Then, in order to be honest and coherent both; such a Christian ought to set-aside the Omni-God concept, or at least relegate Omni-God to subordinate status. 

And instead seek an understanding of God that acknowledges - and clearly and coherently explains - the nature, origin, truth, and goodness of each Man's freedom. 

Note: I leave it to the members of the two largest Christian communions - Roman Catholic and Eastern Orthodox - to do the same exercise for the confessional documents of their own institutions.