That's what Jesus said. However, if MacArthur is commenting on the likes of Bethel, Hillsong, Kenneth Copeland, Joyce Meyer, or Joel Osteen, then he could be correct in his identification of them, because it has been made clear that those pseudo-charismatics are not of the Holy Spirit but of a different spirit.
Because in other areas MacArthur does give sound Gospel oriented teaching, means that he can't be blaspheming the Holy Spirit, because some who is blaspheming the Holy Spirit cannot give the teaching that he does. Remember what Jesus said to the disciples who saw others preaching the good news who were not of their particular group. He said not to stop them because whoever was not against Him is for Him.
So, John MacArthur may not agree with our party doctrines, but he is for Christ, and therefore not against Him, so we are in no position to discredit him merely because he sees, in the limited experience of the Charismatic that he has, that it comes from a spirit that is not of God. I think he, like all of us, is looking through the wrong end of the telescope, and quite possibly, he is looking through the wrong end of his telescope at the Charismatic movement.
He does make a distinction between what he calls "Reformed Charismatics" and does not put them in the same category as the "charismania" ones. His beef with them is that they don't put more effort into speaking out against the lunatic ones. But he is wrong about that, because some of prominent Pentecostals such as Michael Brown, the late David Wilkerson, John Wimber, Jack Hayford, and Derek Prince, gave clear teaching that the "charismania" was not of the right spirit and that believers should keep well clear of it.
If you are going to say that Calvinists are not of God, you would have to put all the Reformers, Puritans, George Whitefield, Jonathan Edwards, Charles Spurgeon and the many others who won thousands to Christ in their time. If it wasn't for John Calvin and his systematic theology, we would not have the churches we have today with the freedom of religion. Remember, it was Calvinist puritans who first settled North America and were responsible for the foundation of the nation.
All my reading of Calvinist puritan literature has shown me that it is totally Christ centred and teaches faith in the finished work of Christ. But then, John Wesley and the Methodist Holiness teachers were Arminian, but also Christ-centred. They preached faith in the finished work of Christ also. So they were for Christ and not against Him. Therefore Jesus teaches us that just because people don't subscribe to our party and its particular doctrines, if they are for Him and not again Him, we should not forbid them, even by accusing them of being against Christ because they are Calvinist, or Arminian, Evangelical, Pentecostal, Amish, or Mennonite or whatever other brand of the Christian faith they are.