Arminians do indeed believe in God's Sovereignty. Just not the Calvinistic view of God's Sovereignty. From Arminian Theology blog:
The point of difference between Calvinism and Arminianism is the definition of sovereignty. On the Calvinistic view, sovereignty means meticulous control (i.e., theological determinism),5 while on the Arminian view, God’s sovereignty necessarily means His complete freedom and authority (or right) to act any way He so wills.
On this view, God certainly has the freedom and authority to exercise meticulous control over every minute detail (though the Arminian can’t see how this doesn’t necessitate God’s authorship of sin), but He also has the freedom and authority to not exercise meticulous control. For the Arminian, if God chooses to not exercise meticulous control, that decision is itself a sovereign decision.
As (Arminian) apologist J. P. Holding writes,“SOME Calvinist commentators point to various passages of specific events such as the selling of Joseph into slavery (Gen. 45-50), the crucifixion of Christ (Acts 2:23), and the military actions of the Assyrians (Is. 10).
And they are not wrong to do so. Yet one cannot falsely generalize from these particulars and assume that God chooses to exercise His right of sovereignty in the same way for things like the moving of a finger.
Perhaps He does, but perhaps He does not; perhaps He does at some times, but not at others.Yet to suggest such a thing hardly removes any sovereignty from God, for a simple reason that I have yet to see dealt with by a Calvinist commentator (though I may see it in the future): The decision to do nothing is itself a sovereign decision.” 6
The point of difference between Calvinism and Arminianism is the definition of sovereignty. On the Calvinistic view, sovereignty means meticulous control (i.e., theological determinism),5 while on the Arminian view, God’s sovereignty necessarily means His complete freedom and authority (or right) to act any way He so wills.
On this view, God certainly has the freedom and authority to exercise meticulous control over every minute detail (though the Arminian can’t see how this doesn’t necessitate God’s authorship of sin), but He also has the freedom and authority to not exercise meticulous control. For the Arminian, if God chooses to not exercise meticulous control, that decision is itself a sovereign decision.
As (Arminian) apologist J. P. Holding writes,“SOME Calvinist commentators point to various passages of specific events such as the selling of Joseph into slavery (Gen. 45-50), the crucifixion of Christ (Acts 2:23), and the military actions of the Assyrians (Is. 10).
And they are not wrong to do so. Yet one cannot falsely generalize from these particulars and assume that God chooses to exercise His right of sovereignty in the same way for things like the moving of a finger.
Perhaps He does, but perhaps He does not; perhaps He does at some times, but not at others.Yet to suggest such a thing hardly removes any sovereignty from God, for a simple reason that I have yet to see dealt with by a Calvinist commentator (though I may see it in the future): The decision to do nothing is itself a sovereign decision.” 6