A Stone in the Shoe

In any apologetic conversation, the goal should be Truth and Clarity, not necessarily agreement.  Real tolerance allows for healthy disagreement about ideas and beliefs, not all of which are true, good, or thought out.  This includes direct challenges to bad ideas without attacking the person.

Asking (Columbo) questions to guide a conversation serves to 

• give clarification of what is believed

• gather information, find inconsistencies or weakness 

• provoke thought with leading questions, making a point, or expose logic flaws

• define their terms by asking, "What do you mean by that?"

• challenge them to explain their reasoning (i.e. their narrative), "How did you come to that conclusion?"

• draw out or expose the consequences of their beliefs, if true or not (e.g. "So what does that imply, or what should be done?") 

The end goal is not an immediate "win", but rather to put a stone in their shoe so that they go away feeling uncomfortable with some aspect of their view.  Realize too that others may be listening.  Your conversation is for them too, not just those in the discussion proper.  The hope is to get them (and ourselves) to come to know what we believe and why.