If you are a Christian, and they come at you like, I would say that you are a Christian, and then argue doctrine with them.  If you can do this, you can debate where they are wrong.  Other than that, you can say that you are, but don't want to talk about it.

I remember running across one some on a corner preaching hellfire and whatnot.  I engaged with them, asked them about baptism and repetence, and they got fed up and left.  Things like that can happen.  No reason to deny anything, just use the Bible to explain why they are wrong.

Every time I think of religion I remember back to when my step-cousins (devout Lutherans) were literally pissed at me when I questioned whether or not the story of Adam and Eve literally happened as it's written or whether it was just a story to give the Bible a proper introduction.

Their basic logic: "How can you believe in God if you don't believe everything the Bible says?"
My response: "The Bible says to stone people to death for working on the Sabbath. How many people have you stoned to death recently?"

Then I would quote Jesus about the Sabbath being made for man, and man not made for the Sabbath.  I would still hold out there is a principle of a day of rest that would best be honored.

Christian leaders need to screen who goes door to door to preach. But I can't blame them for trying. Christianity numbers globally are stagnant at best, and shrinking at worst. The #2 religion, Islam, agressively converts and is now the fastest growing religion. Islam countries promise citizens a better life if they follow Islam in their daily lives, parents strictly convert their children....you don't find many atheist children in Muslim states. Such things are a dishonor in the community. Christians are way too lenient with their children and let them choose their own faiths.

In the end, Christians are just trying nicely to bring up their numbers. Is just how they approach it that needs to change.

I am Christian and I can't stand the Bible heavy, heavy faith based Christians. There is also different branches of Christianity and they have no control over the other. Protestants, Catholic, Anglican, and the pimple of Christianity (at least from the Catholic/Protestant view).....Mormon and Jehovas Witness.

It would be better if people respected what the Christian religion is, and end up speaking of what it is, and let it be, rather than come up with some sort of warped justification of their own doctrinal views to explain everything, appease their inner guilt and bend it so they believe they will go to heaven when they die. This being is what I will often see people evangelizing with flawed teaching that doesn't reflect the Bible accurately.  It also leads to a lot of faking of things.  I believe it is written Jesus spoke of people making converts who then became twice the sinner as a result.

As far as numbers go, I believe it would be appropriate to say, based on the New Testament texts, that Jesus is far more interest in quality, rather than quantity.  Jesus wants the good soil, and people who stay in until the end.