I was raised Catholic and still consider myself Catholic. One aspect of Catholicism, oft ridiculed, is an emphasis on sacred mysteries. In Catholic theology these aren't simply a way to explain miracles. Rather, the tenet is that there are aspects of the world that are unknown and even unknowable. Thus there are limits to what can be theologically positively affirmed or categorically rejected.[1] So to say that a machine could never have a soul is to say too much, at least in the context of Catholic theology.

You're entitled to your belief, of course, but simply asserting the existence of [Christian] souls and an inter-relationship between souls and intelligence isn't sufficient to make your claim.

Discussing souls is probably not appropriate subject matter on HN, but I thought it was worthwhile to make the point that even religions can have and utilize the concept of unknowns to self-limit its theological reach. Technically speaking, orthodox (small 'o') Christians (Catholics, Orthodox, mainline Protestants) only need affirm the Nicene Creed and nothing more, just like, AFAIU, Muslims need only affirm the Shahada. Thus, an orthodox Christian is supposed to affirm the Trinity, the resurrection of Jesus, etc, but otherwise free to accept or reject machine souls, notwithstanding additional doctrinal strictures of particular denominations that might dictate a particular choice.

[1] This is why you see seemingly radical priests quoted as admitting that aliens could have souls. (And also why it's so easy for Bill Maher or Michael Moore to find a priest to make seemingly contradictory and outrageous statements; more often than not the priest is playing them more than Maher or Moore understand, they're just too cynical to appreciate it.) Catholicism is hardly the only religion, or even Christian religion, with such a concept. But it's perhaps gone to the greatest lengths to develop and integrate the concept with modern logic and science.