Yes. There are some people so twisted, so evil, that they are beyond redemption. Many of my fellow Christians will sharply disagree. And I am not saying that any being is totally evil, since I accept the old Neoplatonic and Augustinian view that evil is both an absence of good and an absence of being. Thus, a totally evil being could not exist. Even Satan, insofar as he is a creation of God, is good in a bare metaphysical sense, even though his will has turned to evil.
That said, there are human beings who are sociopaths or psychopaths. Scholars argue about the differences in meaning between the two terms, but in either case, an individual either has no conscience or does not even comprehend the concept of conscience. Some, though not all, serial killers are psychopaths. But psychopaths work in all walks of life. The psychopath may be the operator of a Ponzi scheme. Or two psychopaths may be married, go to a church, split the church, and go on to the next church (or other organization). Many psychopaths are charming; they are excellent actors. But they are different from other actors, such as people with narcissistic, histrionic, or borderline personality disorders. Even a person with borderline disorder, the most serious personality disorder short of psychopathy, has a conscience. A borderline person is extremely manipulative, lies constantly, and is difficult to treat, but some have been helped. But a psychopath, with no conscience, lacks a necessary condition for being a part of any stable human community. In a way, part of that individual’s humanity has been stripped away–whether by genetics, poor environment, or habituation in bad choices–or a combination of these factors–is unknown. Although cognitive therapy has been tried on psychopaths, that will only work insofar as a psychopaths perceives going along with societal norms as being in his best interest.
There are some people whom even omnipotence cannot reach. The mercy of God has its limits on those incapable of receiving it. And a psychopath would see no need of redemption for he has no sense of sin.
Psychopaths who commit murder are beyond help. Execution is the only rational option–the psychopath will never feel guilty or ashamed of his actions no matter how much time he spends in prison. And psychopaths are dangerously manipulative–toward both other prisoners and toward guards. For those psychopaths who are in business, if they commit crimes that harm others, I do not know what the best option is other than keeping them out of society, preferably forever. As for the petty psychopaths who split churches and other organizations, other people who might encounter them should be warned.
Does a psychopath have free will? He does within limits. A psychopath can make good or evil choices; he simply would not recognize them as good or evil. Other motivations are involved in a psychopath’s choices, usually perceived self-interest.
Can God save a psychopath? I don’t think so. The problem is not on the part of God, it’s on the part of the psychopath. I do not understand why God allows such twisted people to exist, and I suppose, like the problem of evil and suffering in general, the answer will be a mystery this side of Heaven.