"Often people avoid God because they see evildoers in the world and hypocrites in the church."
~ NIV notes
I have heard many reasons why people don't want to become Christians and the two above seem to be at the top of the list. People often ask why God allows bad things to happen if He is in charge. John 14:30 says "the prince of this world is coming," Satan is the prince of this world. I don't have an answer why evil is allowed to roam free except that God allows it. We don't know why, but we should have faith that God knows exactly what He is doing.
Hypocrites run rampant in many churches which will do more damage to push out new Christians or people thinking of becoming Christians. The church is for sinners and we are all sinners. If people are not acting like Jesus then don't take offense, that just means you are probably doing the right thing because the devil wants to trip you up.
Remember that the enemy uses Christians all the time when they allow pride to get in between their relationship with God. Don't let the enemy get a foothold because his roots run deep which you may not even notice until it's too late and they are extremely difficult to get rid of.