Well besides the theological issues of placing a barrier between the partners in the conjugal act, condoms provide a false sense of security since many of the cheaper ones have air holes much larger than the HIV virus. They are impermable to sperm but the virus goes right thru it.
Abstinence and monogamy - work every time they are tried.
A penis has to breathe you know.
I'm afraid I can't remember where I heard this illustration, but it's a good one. If the holes in a condom were the size of a house window, sperm cells would be the size of a house. So no problem, right? Well, just one: The HIV virus would be the size of a baseball.
Oops.