The one major difference between Christianity and all other religions is Grace. I'm sure there are many more differences we can find. But Grace is where Christianity goes its own way and stands alone.
While other religions seek to bring their followers to a higher level of enlightenment or salvation by making them work and strive to better themselves (however that religion defines bettering), Christianity says to EVERYONE, 'you'll never make it on your own'.
So bottom line is, the only condition for being a Christian is to believe in Christ and all that he represents. There is nothing else to do. There is no work to do. There is no betterment to participate in. There is nobody to compete with. There is no cause to serve. Nothing is required of you, because it is already understood that there is nothing you can offer to a Holy God that will ever satisfy Him. There is nothing you or I could do to ever reach Him. He understands that. That is why He sacrificed Himself; because He wanted desperately to change that, and wanted desperately to be with you. Not so you could "be better", but because he just loves us.
So that's the view from down here. From up there, it's a different view.
Christians and those who call themselves Christians (by that I mean people who culturally or by heritage give themselves this title), have a tendency to hold a higher view of themselves. For that matter most people do, regardless of religious belief. It is our nature to do so. We want to believe we can achieve great things for our creator, if we believe in one or more, or we want to believe we can achieve great things to gain enlightenment.
So we build our proverbial towers to reach God. After all, the view from the top makes more sense; or at least that is what we believe. More than anything else, by nature and instinct, we believe we can reach the top (whatever the "top" is) on our own, and that it is our duty and our right to do so. Nobody wants to be at the bottom. Nobody wants to see themselves as "lesser". Nobody wants to feel small.
For Christians, it is to our disadvantage that we share this nature with the rest of the world. It's a disadvantage because it is exactly this nature that keeps us from experiencing our faith at a deeper level.
After all, if we believe the promises of Christ; that by His death and resurrection we are saved, but our nature tells us there is still something we have to do to reach Him or know Him, then we are truly at a great disadvantage.
So what is the view from down here? It is the view that says there is nothing I can do to make Him love me any more or any less than He already does.
It is polar opposite from the the view up there; the view that complicates and clouds our vision of ourselves and God, and tells us there has GOT to be more to it than that.
The view from up there is called many things. I like to call it our sin-nature. Others call it original sin. It's the view that says, 'I can do this'. Some people think sex is sin. Others think being a politician is sin. Still others think gay=sin, abortion=sin. These days some people think being a Christian = sin (or mean, because most of those people don't believe sin exists).
"Sin" is our nature, and our nature is to rebel and reach whatever we are trying to reach on our own steam. Basically, 'sin' is who we are. We can't categorize it in to specific acts of disobedience.
To some this sounds horrible. To others it sounds simplistic. I guess that's why some believe and others don't.
For me it makes sense. I'm not saying 'This is my truth'. I'm saying this is truth.
God's grace is the reason Christ turned the world on it's head. There are many religions in the world; I hear that all the time. I also hear, 'With so many religions, how can you believe that Christianity is the only right one?'. Speaking from personal experience, Christianity is the only religion that, when approached honestly, makes sense in the whole realm of existence. It's the only worldview that stands on it own, because it is the only one that says you cannot know God until you recognize your utter and complete need of Him.
And no, I don't think this is arrogant. I don't think it is arrogance to say, "I can't do this on my own". There is more arrogance in saying, "I can make this happen on my own".
Perspective is a hell of a thing. I'll choose the view from down here. It's definitely not a comfortable place to be. I'd rather be where I can believe there is a "Secret", or a place where I can experience my "...Best Life Now". But then again, Jesus never said it would be easy.