The fallacy of God's will vs. Man's will
Those who argue for hard predestination (high Calvinism) view freewill as a threat to the sovereignty of God. This is not so because every Christian doctrine hangs upon the sovereignty of God in orthodoxy. Hence the slightest break in the sovereignty of God cannot be permitted. Even the doctrine of man's moral freedom is actually meaningless apart from God's sovereignty.
When I see people arguing against any freedom, I know that the root of such thinking lies in the thought of man's will hanging over God's will to such a degree that man's will challenges and defies God so as to constitute a threat to God's will and purpose in creation.
This unsatisfactory concept of man's freedom in relation to God's sovereignty could be likened to a set of balancing scales with the weights set against each other. In this view either God's will is thwarted by man's will or man's will is thwarted by God's will. In either case one of the two is victor and the other vanquished.
If man is afforded no moral responsibility apart from the agency of God's own, then it cannot be said that there are any other wills other than God's own. Hence, whatever your "will" is, it is God's will working. Therefore in what way are men held morally responsible? They cannot without destroying the concept of a just God and pitting the attributes of God in opposition with each other. Hence the sovereignty of God cannot supersede His justice.
Because God is not internally at opposition with himself, there must be a flaw with the view of pitting man's will and God's will in opposition.
Hence it seems to be more in keeping with the biblical teaching (God is sovereign; men are accountable) to illustrate the proper relationship my drawing a large circle which typifies God's will and them drawing a small dot within that large circle which represents man's moral freedom within God's will.
With this model God has sovereignty created morally responsible beings who are strictly limited by God. God makes the rules while man is allowed to exercise freedom within the limits set by God. Hence man always lives in an environment where God is Master.
With this model God's will and mercy sustains man's moral freedom. In fact with this model, God has made man in such a way that man is under the constant necessity to make moral decisions. With this model man cannot choose evil and reap good, nor can he make his own rules for the moral life. Neither can man dictate the terms of his own salvation.
Consequently the problem of God's will vs. man's will is resolved and there is no need to argue against man's moral freedom to defend God's sovereignty.
Abstract and cited from Mildred Wynkoop, 1967, Foundations of Wesleyan-Arminian Theology, "God's Will and Man's Will" Kansas City, MO: Beacon Hill Press of Kansas City, pp. 91-92