A child may believe they "love" Santa, but in actuality, they love the concept, the idea, of Santa. Because Santa does not exist. She may feel that she "connects" with the concept or idea of her god which she has conceptualized over her lifetime from many different sources. But the substance, the most important thing, the proof, that she can't produce. This is why the statement, "it's not a religion, it's a relationship," is so delusional. A person cannot have a one-sided relationship with the unsubstantial concept of a god, it cannot connect back or interact with them.

This post I wrote may help you to understand why people believe against all logic and reason: "Humankind has evolved to the point that they are conscious of their own mortality."

"Religion is not a matter of God, church, holy cause, etc. These are but accessories. The source of religious preoccupation is in the self, or rather the rejection of the self. Dedication in the obverse side of self-rejection. Man alone is a religious animal because, as Montaigne points out, it is a malady confined to man, and not seen in any other creature, to hate and despise ourselves." - Eric Hoffer, Author of The True Believer

As a former Christian I can understand the consideration that it is about "relationship " not about some atheist definition of this thing atheist calls religion.

Biblically what is considered religion has been written for at least as almost 2000 years. Biblical students would then see that if they wanted to be religious then they help widows and orphans while avoiding worldly corruption.

Religion ... pure and faultless is this: to help widows and orphans in need and avoiding worldly corruption. James 1:27

This religion has nothing to do with particular "God thingies" as illogical atheist label what ever it is they are calling "religion ".

I have further discussion pertaining to this topic. You could go there and read over what I have posted and make comments for further discussion of what I could explain to you. Click here, or go to like from my profile "Illogical atheists guide for ending Christianity "

Yeah, I went through the same phases that you went through. That angry phase was fun, no? But it gets tiring, too.

I think that my own sister is skeptical (though I don't know for sure; we don't talk about it,) but her girlfriend of fifteen years is a Christian. I don't know how she reconciles her sexuality with her faith (and she doesn't go to a church that accepts it, either! She goes to a church that's very much against it!)

I don't understand it. Maybe there's nothing to understand about it, except to acknowledge that people are stupid. Even if they're smart. We are flexible creatures, to be both smart and stupid at the same time!

Hello and welcome to the site. I do not really have an answer to the question of, what you could do differently. But it is worth noting that people often become most defensive and outwardly committed to their beliefs, at just the time when they are beginning to have inner doubts. Therefore don't push that will make things worse, but do set a good example of being a good person as an atheist, and your sister may one day surprise you. I don't think that you have a better strategy, than that, available sorry to say.