Buddhism sets a very different spiritual goal from evangelical Christianity. Where a Christian finds eternal life in redemption in Jesus Christ, the Buddhist seeks a cessation from eternal existence. Not only does this present a challenge to the missionary in a predominantly-Buddhist host culture, but it also challenges the evidential apologist. How does he approach "common ground" with a Buddhist, when there is no common ground?
On the other hand, the presuppositional apologist has a clear opening with the Buddhist.
According to Buddhism, the destiny of the individual is the consequence of karma. That is, that his future incarnations are buoyed up or weighed down according to his good works or wickedness in this life. The goal of the Buddhist is to become selfless, a nonentity, thus escaping from the cycle of reincarnations. Also, according to Buddhism, all sentient creatures, even deities, are subject to this cycle; there is no objective umpire outside that judges the good or evil that the individual does.
Here is the presuppositional opening: the Buddhist depends on the inner marks of his conscience to judge his own works. While claiming not to know the God of the Bible, the Buddhist is guilty of precept stealing, the unspoken admission of Biblical truth to sustain his unbelief.
In this case, the Buddhist is relying on conscience, the inner testimony that his works are consistent with, or contrary to, the law of God. In fact, the Christian understands that conscience is the result of the law placed in our hearts by that same God. We see this in Psalm 37:31, where David testifies that "the law of God is in his [i.e., the righteous man's] heart." And in Jeremiah 31:33, where Jehovah, the God of the Bible, says, "I will put My law within them." This is an aspect of what Paul tells us in Romans 1:18-25, that the unbeliever knows in his heart that Jehovah is God, but suppresses that knowledge in unrighteousness.
Thus, with the Buddhist, the Christian must expose this tacit admission, both that Jehovah is God, and that He has placed the knowledge of righteousness in the hearts of men. Thus, the Buddhist is accountable, not to a faceless karma, nor to any opportunities for new lives, but rather to a righteous Judge, with only the alternatives of eternal life or eternal death to come.