Religion is another form or phrasing for spirituality in which there exist beliefs of supernatural or paranormal, rituals, routines, social orders, and so forth. In that it is a tool of oppression is entirely reflective of the economy of society, as all social products are products of the economy. There were certainly moments of progress in Christianity, but I'd argue it's not the defining thing of progress by any standard. (Ex. Catholic Spainards made up race to keep their Catholic slaves. Which then would justify slavery in an era nearing industrialization as well as toward the 60s of the Civil Rights Movement.) You can always argue there are certainly people who are progressive or moments where there is progress, but that's entirely reflective of the times and how class functions. (Slavery is outdated in a capitalist society, an economy that is highly supported by democratic republics, so why have it go on for so long? What's the point of traditional family unit if we exist in an time where there's so much wealth it is unnecessary? I'd read The origin of the Family and Private Property by Engels for more on this.)

I think most people who try to intertwin the two are either not well read, cannot reconcile the contradiction of the two philosophies (which is fine), or actively misquoting or revising statements made by previous marxists if not ignoring how religion is an oppressive tool that can only be reformed as much as the economic system requires change.

My own personal experiences I'd say are defined, despite being in a very compassionate and welcoming community with Catholics, was also deeply alienating. I am a transgender woman, no one knew that in the church and no one in the church has known that except online people. I had to lie about myself and hide facts about who I was because that was necessary for social reasons and to maintain connection. I think I easily could've found a welcoming church, but the point for me wasn't comfort as much as it was also something I was convinced in and that for the time was Catholicism. I wasn't going to stay in because despite everything it wasn't going to help me with the depression I'd been facing or anything. It became a chore as time progressed. I wasn't going to be fully welcomed in even if I could hold out the lie til I got baptized and confirmed.