This same insane ability to jump to conclusions extends in to the church. I had a preacher once who could barely read. He would stand in the pulpit, hoop and holler about some random topic, then stumble through some verses--and the congregation would "Amen" and "Preach!" this man like he was saying something worth saying! I've heard so many misconstrued ideas of what the Bible says not just from the ordinary church goers and preachers, but even disbelievers. I must admit, I laugh when a disbeliever tells me they don't believe because of something that isn't even in scripture.
Truthfully, somethings people are jaded about are probably not that important. An instance being the idea that an apple was the forbidden fruit. Genesis 3:1-6 is where The Bible discusses the forbidden fruit and no where does it mention an apple. The common assumption of it being an apple was probably introduced in 1667 when Paradise Lost was published. Does it matter in the end what kind of fruit it was? Probably not.
The important things are the things people cling to as though they are fundamentally part of Christianity, when they actually are pagan rituals or man made traditions. These are the things I see constantly spoken and written, and think "Have you even read a Bible?" The two that bother me the most come in scheduled, predictable waves.
Every Sunday, there is an influx of people proclaiming their love for God, talking about how they went to church, how "heathen" it is not to go... And yet the Sabbath is on Saturday; man moved the day of worship to Sunday in the Council of Laodicea (Canon 29) over 300 years after Jesus. Sunday was the day of worship for people who practiced sun worship (surprise--that's why it's called "Sun"day). Many of the sun worship practices were fused in to Christianity around this time actually. So, essentially, what all these people say on Sunday is "I'm partaking in pagan traditions even though The Bible states that God hates this, and I'm judging you, which The Bible also speaks against, for not partaking in pagan traditions."
The other occurs during Christmas. When I was young, a friend of mine from the Jehovah's Witness denomination told me she didn't celebrate Christmas because it wasn't in The Bible. At the time, I didn't comprehend what she was saying; the birth of Jesus is documented in the Gospels, most commonly relayed from Luke. As I got older, and studied the Bible more, I realized what she meant. Not only is it obvious that no date is given for Jesus's birth (which would have been given if God intended us to celebrate it), there is no mentioning of it being celebrated anywhere in the New Testament. In fact, birthday's are mentioned in The Bible on when speaking of the non-believers (Genesis 40:20-22 and Matthew 14:6-10, for example). Why, then, are you telling me that Jesus is the reason for the season? Christmas is a pagan holiday (ever wonder why it miraculously occurs during the same time as Santa Claus's visits?)
Jesus warned that during the end times many would come claiming His name and many false prophets would plague the nations. The Bible shows countless times that the biggest stumbling block for believers is/was falling into pagan customs. He already told us that many would be fooled by the antichrist. Furthermore, simple research shows that "anti" not only means opposite, but also in place of (click for source). People are following man and pagan traditions in place of Christ (i.e. people are following the antichrist). Non-believers see this hypocrisy and run in the opposite direction because of this confusion (not just Sunday and Christmas, but we'd be here all day if I went through every example).