Thanks for reading, Sarah! I wouldn't attempt to speak for those who have walked away from faith. However, I fully understand that what many have experienced and witnessed inside a church and/or a "christian" community, family, or culture can lead them to conclude that the "christianity" they experienced is not the way.
There are bad elements and bad actors that parade under the "christian" banner, and that is discouraging to me. I have often debated whether to continue using the label "Christian" when talking to those who don't share my beliefs because it is impossible to know what that person's experience of "Christians" has been
But the term, first applied to one of the very first church bodies in the months after Jesus' resurrection, simply means those who follow Christ. And I think that is where the root of the problem in "christianity" (especially Western christianity) lies. Many who call themselves "christians" today are more committed to an ideology, a political platform, a certain theological strain or doctrine or denomination than they are to the person of Jesus Christ. If everyone in the church were beholden only to Christ, I feel we'd see a different story being written today.
I cannot argue against those who say they have found more peace and happiness outside of the church and religious experience they came out of. And it would be foolish for me to try to address those cases in a blanket manner.
What I can say is that we are immortal beings made for eternal union with the immortal God. We achieve that union through the Way of Jesus Christ (who is Himself the Way).
While it may sound nice and pleasant to say that there are an infinite number of ways and that any way is just as good as another, logic fails this premise. (Trust me, I'd be all about going my own way if I thought it were valid.)
If you find that you continue wondering about these issues and other "big questions" of life, I encourage you to read "Notes from the Tilt-a-Whirl," by N.D. Wilson (https://www.amazon.com/Notes-Tilt-Whirl-Wide-Eyed-Wonder-ebook/dp/B002EPNHHW/).
And, if you want to consider the Way of Christ, please read, "Mere Christianity," by C.S. Lewis (https://www.amazon.com/Mere-Christianity-Lewis-Signature-Classics-ebook/dp/B002BD2UR0/). You probably already know this, but he abandoned the Christian faith as a young man, became an atheist for years, and then found his way back to Christ. Or, perhaps, Christ found him.