Once the basic movement/stance/strikes are learned then you move to the second stage: Mechanical.  The Mechanical stage is where you know the moves but you must practice repeatedly and consciously tells your body to move in response to the attack.  With much practice you move to the third stage which is Spontaneous.  This is the stage in which you can respond instantaneously, without thinking.  Similar to the idea of "Flow".  This is also where you will "Graft" other techniques and respond to what your attacker is giving you. This where the individual adapts the technique into their own expression.  You deal with the "What-Ifs?" at this stage.  "What if he throws___?  Or What if it doesn't work?"  What are the most common attacks your students going to face on the street?  If you aren't showing defenses against pushes, grabs, bear hugs, sucker punches, than you aren't teaching them self-defense.

Well, apply this to responding to questions of skeptics or seekers towards Christianity.
Instead of physical defense it is spiritual defense.  Often we give an inappropriate response because we are fearful.  We are not experienced, we have not encountered the attack before, we are on unfamiliar territory.  So we are studying through the most common questions people have about our faith.  These are found in most apologetics books, our text we used was "I'm Glad You Asked"  by Ken Boa or Larry Moody.  Questions such as "Is there a God?"  "Why believe the Bible?"  "Is Christ the Only Way to God?", etc.  These are basic questions to understand and be able to answer.  So we give the foundational answers from the Word of God.  Teach the basics, like the Embryonic stage.  Then we Role-play and have them give their response to the questions.

As you get more experience in witnessing and apologetics you will learn how to flow and go from question to question.  Instead of being defensive you will learn to direct the "attacker" in a proactive way.  You will know how to share the truth of God's Word,  and with the Holy Spirit's power lead them to Christ and the Cross.

1 Peter 3:14-15.  We need to be ready to give an account for the hope we have, yet with GENTLENESS and RESPECT. Physically and spiritually our goal is not annihilation of our attacker.

This is just one of the ways that the physical aspect of kenpo is just a reflection of spiritual training.