As a non-Christian, I've seen evangelicals make a fair number of attempts to proselytize me. With their Bible in their hands and a worn smile on their face, they patiently try to make me understand that Jesus Christ is my only salvation, that I've been living my life wrong all this time (even though they have no idea what it means to live a Hindu life).
Although I oppose proselytism on principle, I sympathize with the intention. The idea, it seems, is that it feels miserly and selfish to have found something that has been such a positive and transformational force in one's own life and not share it with others. One wants to spread the "good news," so to speak.
But in spite of my sympathies, even well-meaning and clean-hearted evangelicals come off as annoying and intrusive—and it's not an accident.
The problem is that evangelicals forget one of the most fundamental rhetorical dictums: know thy audience. For some reason, evangelicals seem to believe that the best way to talk to people who do not believe in the validity of the Bible is to endlessly quote the Bible. They like to start with John 3:16 ("For God so loved the world..."), take a tour through Matthew and Mark, and then make a powerful close with John 14:6 ("I am the way and the truth and the life..."), the clincher that unequivocally proves the necessity of conversion. They look at you with eyes (and sometimes mouths) that say, if it's written in the Bible how can you contradict? And if you do contradict, you only get another Bible quote.
This is surely an exercise in futility. So, evangelicals, if you are to undertake the very difficult task of proving that only your way of worship is legitimate, please read up on some rhetoric first.