One of the few truly interesting apologetics Christian's have is love. Love in the Christian sense is interesting because it is so counter cultural to the world.
Christian love differs from love in the world in that it is beyond reason. We love not because of what is, but what could be or because of what Jesus has done.
You see Christian love is not without reason but its base is in an event in the past or in future possibility. Christian love often ignores what is.
That is why the early church spread so quickly. There was something very distinctive about their love.
Argumentation or debate are apologetics with little use. Most debates are ended emotionally long before the intellect is engaged. You see that man does not like the Christian message about himself because he must first accept his nature.
It is good for man to accept his nature. But he does not like the message.
Ultimately the solution of free grace through faith is dependent on the realization of need. The good news of salvation is only good when we realize the actual state we are in.