This video linked below is simply excellent - with very helpful, instructional tips and strategies upon dialoging with unbelievers and helping them to see important concepts and truths that have the potential to open their eyes to God and Christ. The discussion and ideas are from DAVID Geisler, son of the late, great theologian, Norman Geisler, as he takes up the points originated by his dad. Everyone can learn powerful ideas from this video:
https://www.youtube.com/watch?v=YoSbUhmptwQ
As an aside, I would unflinchingly say Norman Geisler has influenced me more than any other theologian or Christian thinker - what a mind God gave that man!