Ha! Some friends belong to a church with a strong dualistic theology, featuring a very active Satan fighting against the Creator - anyway, the point is they teach that the devil won’t abolish churches so much as rot them out from within ( thus, the need for constant vigilence in church lest the pastor or anyone try to water down their doctrines). They say to be especially wary of doctrines being rendered unimportant, sidelined, or just spiritualized into a practical meaninglessness —- rather than Satan actually trying to directly confront or destroy them. Result if not “on guard?” A church can become an empty shell of its former self. It’s like your friend!s thinking- he thinks he’s as much a Christian without church as those folks who are in it. Viz, he thinks there’s nothing in church of any value to him. Sadly, this is pretty accurate for many churches and synagogues in this modern age. I hope your friend happens to visit a “real” church someday, because if he just walks into any number of today’s secularized- liberal- progressive churches.... his perception ( that there’s nothing of value there) will only be reinforced.
When I was young I could never understand the phrase, “...and the Gates of Hell will not prevail against my church.” The image it conjured up for me were these large Medeival gates being battered pay the spire of this inverted building in the air. It just didn’t make sense. It was like an epiphany. My problem was I was seeing both objects as being “passive”, physical entities. A church ain’t a building and the Gates of Hell ain’t a place.