One can teach tolerance without necessarily exposing one's children to EVERY opposing viewpoint in the world. I teach my children that people believe many different things, and what one person believes is truth may not be what another person believes. I've got to set certain standards, though. Being a proponent of IDIC doesn't mean that I want my kids surrounded by people and concepts which contradict the moral principles I'm trying to teach them. To paraphrase from the New Testament, a Christian should love his/her neighbor, but be IN the world, not OF the world.
Being pleasant to everyone does two things. It demonstrates to my kids and to others that I practice what I preach, and it indirectly evangelizes, for if just one person looks at me and says "I want to be like that" and in the process comes to know Christ, then I've done my job in this life. Loving someone doesn't mean you've got to agree with them. Sometimes you have to love someone DESPITE the fact that you disagree with them.
