I'm non-religious, and my ex is moderately religious. However my daughter has almost always been an atheist. She somehow picked up on the bullshit very early in life. She was happy to know that I was also logical and aware.

My own family just respects different views and avoids the topics of arguments. Holiday gatherings and reunions of any kind maintain a ban on any political or religious discussion to avoid a divide. I try to live by that as best I can with friends and acquaintances. If someone starts something up I try to steer it towards respecting differences or just walk away, even with family. My brother has been very conservative and religious the last 10ish years or so and I've had to turn from him now and then. He's lately learned that if he is in a mood he should avoid me because I'll walk anyway.

My husband's side is full of bickering more often than not and quite honestly I don't care for spending a lot of time with them if I can help it. Don't get me wrong, I love them dearly and am happy to spend one on one time with any one of them. I just can't stand the constant bickering when there is more than two of them together.

It doesn't have to be a minefield. I deconverted during my second marriage, and my wife, who remained a good Methodist until her death, was unperturbed by it. Our relationship was based on something other than religious ideology, like, oh, say mutual respect and common interests grounded in who we were as persons, not in what we believed. But I was darned lucky. Most religious conservatives can't separate their identity from their beliefs, and so to not believe along with them is a threat to their very existence.

If your family is toxic and controlling and intrusive, my only advice is to treat it less as specifically a religious problem than as a character issue that religion amplifies. Because the solution is not for them to change their beliefs, necessarily, just to mind their own business. My extended family has been excellent at minding their own business so there has been no problem. The extent of our dialog on the topic was that one of my surviving brothers asked me point blank a few years ago if I didn't believe in god anymore. I said no. He said, "that's too bad", changed the subject, and never brought it up again. Nor has he ever mistreated me about it. It helps that I haven't been a douchebag toward his beliefs, either.

The key in these situations is to have, clearly state, and enforce healthy interpersonal boundaries. In this case the boundary is, "my existential beliefs are my business and it's nothing for you to take personally or attempt to control, if mine differ from yours." If you put it that way it's less likely to devolve into a pointless touche-kicking contest over beliefs. Beliefs aren't really the issue, it's being impertinent and controlling and meddling in your personal affairs. If you keep bringing it back to the basic concept "this is none of your business" they will have a much harder time disputing that.

My ex comes from a Southern-baptist /Catholic family. He himself, mostly rejected organized religion but still sort of believes in Jesus.
I come from a UU family that practiced Zen Buddhism as a philosophy.
As you can imagine, from day one there were issues with his family. They tried to "save me", they told me that they feared for my child's soul because I allow gays and Muslims in my home.
Utter nonsense..
Over time because we moved far enough away from the majority of them, it was just avoided.
During holidays, I would have to contend with his mother's opinions which weren't as radical but very annoying nonetheless.
Example: At thanksgiving we always say thanks to the turkey for giving up his life and then we each say what we are thankful for. She got really upset because "animals don't have souls".
Our kids are taught science and logic and she will argue that the kids need to learn to respect her refusal to believe in evolution. My kids get super offended.
I am not with my ex any more and I will say that my oldest, whom is a total STEM brain doesn't go much of anywhere with my ex's family because she finds them offensive. My middle daughter is better at dealing with them but she has attended the U.U. church more and has a little more tolerance for religious beliefs.
We celebrate "Christmas" as a secular holiday/Yule/Winter Solstice and the same with Easter/Spring Equinox. My kids are taught the history of each holiday both pre and post Abraham religions.
Now when thinking about dating, one of the first things I say is, "I am not a Christian".

I'm atheist and my ex is Lutheran. He wasn't really much of a church goer but was definitely a believer. I told him I was completely fine with our kids growing up going to church, mainly because Lutherans are pretty relaxed and not super strict. I did say that he would have to be in charge of religious instruction and bringing them to church. Also that I wasn't going to hide my atheism and as they get older they can decide for themselves.

Jump forward a few years and we have 2 daughters. Guess who gets stuck bringing them to Sunday school. My youngest was painfully shy so I would have to sit with her through class. Biting my tongue to not argue with the teacher. After 3 years I put my foot down and said it was ridiculous that I was the one taking them and unless he wanted them to grow up to be heathens like me then he'd better step up. Needless today, they didn't go to Sunday school or church after that.

I don't navigate, I trail blaze... With a tank.

Thankfully, I don't have this problem. I can't imagine what I'd do if I did.