I should hope he exists, because that would mean that life has an objective purpose.
That's great and all, and I really hate to keep raining on the parade here, but I'm gonna have to throw out another "what about" moment. What about people who live for like 6 years, then die of cancer, leaving eternally broken parents that didn't deserve that? There are so many variables, where some people never had a chance. What about people born into wars in the Middle East?
Like I said before, if I believed in God right now, I would still not be a Christian, given my heavily conflicting views on the Bible and the fact that many Christians have used their own beliefs to hurt others. Entire wars have been fueled by that.
God gives and takes away life based on His plan. The six year old in your case would go back up to Him because children and the mentally handicapped are innocent in His eyes. They're not capable of being able to comprehend why we need a savior, so they get to go to Heaven.
We live in a fallen world. There's no getting around that. But He places us in certain situations and reveals Himself to us in His own ways so that we may rise above our situation and overcome the world through Him. He demonstrates His power through His people being loyal to Him and loving others despite the horrible conditions they live in.
I myself have autism. I always felt lesser compared to other people and never felt like I belonged anywhere. Not with "normal" people, not with other "autistic" people. Nobody. I even felt like I was disgusting and not worthy of passing on my genes to the next generation and should never get together with a woman. I held onto this idea that I was an evolutionary dead-end because of something I had no control over, and that there was a good chance I'd die alone.
I developed a hatred for other people due to my self-loathing. Put them all at arms length because I didn't want to feel hurt, while at the same time desperately grasping at any female attention. I'd allow myself to consume porn and fantasize about women to escape my reality. All those things did though, was isolate me and make me hate myself even more.
Then, I decided one day to give Christianity a try. But I was one of those people who wanted Christianity for the benefits it provides without actually living the way God wanted. I still wanted a woman for selfish reasons. I didn't want to "love" other people.
Then I read Genesis for the first time. I always loved the dynamic between a man and a woman, how we're built so different, and how we reproduce through each other. To the point where somewhere deep inside, I didn't believe it was any evolutionary accident. God ended up confirming that once I read Genesis, and I believe that was the first time I actually decided to start listening to Him.
From there, it was a gradual transformation as I read the entirety of the Bible over the course of a year. I grew to better understand the world we live in, and why people act the way they do. Why we're all fixated on certain things. Why there is so much evil in the world, ect.
I eventually grew to understand that the way I was born wasn't an accident or a cruel joke. He purposely made my brain the way it is for a reason and that reason became clearer and clearer over time. More and more of His truth was revealed to me, why we act the way we do, why we stray, and why we're so fascinated by certain aspects of creation.
It got to the point where I actually started going to church, finally made the decision to quit masturbation, and got myself baptized.
Just a few months later, God spoke to me again through a positive review I made of a fanfic I made. He wanted me to make a book. I always loved writing and I also loved romance, but I never felt like I was capable of making a book. But thanks to His teachings, I realized what I was missing. Him.
And now here I am, two years later, preparing to publish a Christian Romance hopefully sometime next year. I had to learn a lot about proper writing and unlearn a lot of bad habits and struggle with self-doubt, but I feel like I'm at a point where I can get it out there. If only so I can get started on my next book.
I still have my struggles, occasionally fall back into sexual sin, and wonder if I'll ever have a wife of my own. Even when we're saved, we still have to deal with our sin nature. But I at least know I have a Father who loves me and will take me home when the time comes. I won't be alone.