Salvation is free -- no doubt. It's not by works -- no doubt. However, the free grace movement doesn't represent biblical grace. From the perspective of a lost person, what a deal. Not only is there no works involved, which is a deal, but he gets to keep his old life too! He doesn't give up anything, not even his own will. He keeps that too. It's not a hard sell for the "evangelist," that's for sure. The biggest problem is that this is not how the Bible presents it. It reminds of a lot of other false gospels in that it takes a part of salvation and really focuses on it to its own distortion.
"Free" is the part of grace that it obsesses with. And for grace to be "free," it must be less than a biblical faith, which results in less than biblical grace. When someone does finally live for Christ, it's not because of grace, which is what the person says is the reason he's saved. If he is "sanctified," which he isn't, because he isn't justified, then he is sanctified by himself, even though the grace is free. We know it's himself, because he doesn't do it for awhile or ever. If it were grace, he would start living the Christian life right away, because that's what grace does. That is the power of grace.
"Free" also means "free" from sin. The free grace people so much can't have someone be free from sin, that they actually say, and are proud of it, that someone doesn't ever live the Christian life and is still saved. That's their idea of free. And then if you don't agree with that, you're an apostate. Fine. I gladly renounce what I'm calling the free flesh movement. It isn't grace. It is an occasion to the flesh. Paul told the Galatians not to use their liberty as an occasion to the flesh (Gal 5:13). The word "occasion" is a Greek word that is a military term, meaning a base of operations. Liberty is not a base of operations for the flesh, which is a perfect description of the grace movement's understanding of grace. Grace isn't one of those base of operations, but that movement makes grace to be that. That isn't God's grace, but man's perversion of grace.
And if this free flesh isn't grace, which it isn't, then it also isn't faith. Faith comes by the grace of God and it is exercised for the grace of God, which changes someone. Grace isn't a garbage can, but a cleansing agent. The free flesh people make grace a garbage can. You just keep living like you were except with grace now swallowing up the sin. Romans 6 says you are dead indeed unto sin when grace abounds. Grace cleans up your life, not just takes the same old life and trash compacts the sin as the "believer" keeps practicing it.
The proponents of free flesh distort so much of scripture to justify their position that it is difficult to undo it. As I've written before, you would have to write a whole book to answer their material. For any one of them who cares, Thomas Ross has given them a place at least to start at his faithsaves.net (here, here, here, here, and here). They change the gospel.
In short, the free flesh leave out the true identity of Jesus Christ with His Lordship. You must believe Jesus is Lord to be saved, and if you believe He is Lord, because you know what that means, then you want to follow Him. This includes repentance. It is why they can't have repentance be necessary for salvation, and if they do, they have to redefine it to something that is just intellectual. They say that faith is all that is required, but in fact that don't place their faith in the biblical object of faith, a scriptural Christ, but fall short of that. They allow a person to remain a rebel and an idolater, not to be repentant of either of those and still be saved.
As I've talked about, there are many of these people in both evangelicalism and fundamentalism. Fundamentalism often talks about separation from evangelicals because of their perversion of the gospel, but they do not separate from these fundamentalists who believe the same false gospel. Galatians 1:6-9 especially should induce these fundamentalists to clean up their own camp. To do so would mean going fully unaffiliated. They should.
I don't think the free flesh movement is the most dangerous religious movement today, but it might be the worst. Some might think that a church allowing same sex members, something like that, is the worst. The worst is giving a false gospel that inoculates someone against the real thing. The adherents are not only not saved, but don't know that they are not saved. Maybe nothing could be worse.