from Monergism.com

Semi-Pelagianism, Arminianism or Grace Alone

In semi-pelagianism man's will precedes God's grace. In Arminianism God's grace precedes man's will (but still ascribes faith and repentance to each man's personal wisdom, not to Christ ALONE). But in Divine monergism (grace alone) God mercifully gives man a new heart (Ezek. 36:26), renewing his will and affections, which makes his choice certain and effectual (Jn. 6:37).
It should be noted that Arminians are adamant that they teach salvation by "grace alone" and would take offense if someone were to say otherwise. While I acknowledge that this is what they universally declare, but we are countering this assertion by saying that their theology is not consistent with this declaration. What most Arminians really mean by "grace alone is "faith alone" which is a related concept, but not the same. The problem here is that they rightly affirm the biblical doctrine of salvation "through FAITH alone", but they do not differentiate this concept enough from the biblical doctrine of "GRACE alone", at least in any historical way the Bible or the Reformation speak of this issue. The phrase "grace alone" has always historically signified that Jesus or His grace is not merely necessary for our salvation, but sufficient to save us to the uttermost. Jesus provides everything we need for salvation, including a new heart to believe. In Arminian prevenient grace, on the other hand, Jesus provides no such thing, even by their own reckoning. It claims to lift the natural man out of his depravity, but that man remains unregenerate (has no new heart). In other words it places man (against his will) in some kind of semi-regenerate state, (which the Bible, of course, never speaks of). And then makes the sinner himself the ultimate determining factor in his salvation, which means he ascribes his repenting and believing to his own wisdom or humility and not to Christ alone. Consider, If two persons receive prevenient grace, and one person believes while the other rejects Christ, what makes them to differ that one had faith and not the other? Why did one believe and not the other? It was not grace since they both had grace, so obviously something other than grace made them to differ? Jesus declares another way. He said, "...all that the Father gives to me will come to me" (John 6:37). In other words He ensures that all persons the Father has given to Christ will believe the gospel. Jesus is declaring, in no uncertain terms, that salvation from beginning to end, as the author and finisher, is of the LORD alone, not a cooperation between man and God (Rom 9:15, 16, John 1:13)