There are as many reasons as there are people who aren't Christian I'm sure. But I'm going to make some guesses based on my own experiences of myself (Yes I'm intending to communicate my own reality and hope it helps you.) I can't be exhaustive in other words because it would be too exhausting.
It is often said that non-Christians are tired of hypocrisy. I can easily understand this because I'm tired of hypocrisy in all other people beside myself...no, I'm tired of myself too. The problem is that Christians truly aren't supposed to be hypocritical. In reality, non-Christian people have every reason and can legitimately BE hypocritical and it makes sense. The non-Christian people, I believe, know this intuitively and find it abhorrent that someone would claim to be "in Christ" and a "New Creation" but really don't act any differently than anyone else. Where I see this in myself I'm damn tired of it too. The problem is that our lives aren't really changed though we often claim they are. I think what is often meant is that we've decided that we're "betting on Jesus" than giving our lives LIKE Jesus and this is a serious problem which makes Christians seem ridiculous.
Another thing is that many Christians think more like "Precious Moments" greeting cards than they do in any dimension of the Cross...in any form of self-giving and sacrificial love. Overly sentimental views of Christ don't fit the Son of God. Like Jesus Christ as "cuddle bunny" or "best friends forever." Ick. Get rid of this view, please, though it might be nice for you to have "God loves me" napkin rings this will not save anybody from anything.
I should have called this article, "Another Thing" because I have another thing...Telling people about Jesus is good. Right? The problem is the sugar-candy version doesn't meet people where they actually live. People need to know that Jesus Christ is more than a story but that He has actually affected your life and how. Like the old saying goes, "You can't be a Christian without Christ." I agree with this but what does it mean, truly, to you to "have Christ?" Does this mean that now you've decided not to cheat on your taxes? Or speak harshly to a loved one. People want, and should be able to expect, results. Do you live like everyone else or has God actually changed your life because you call on his Spirit to help you? Christians must realize that we are poor...poverty stricken with a true inability to love. I have difficulty loving other people and I often forget to ask for the Lord's help to love others. I forget who God is and who I am...it's easy to do.
All in all the bottom line is our inability to love and how we Christians truly need to call on God to help us...quickly...constantly. If not we're just ridiculous...you know it.
