- Religious Man: These are the kind of people that used to predominate all over the world, and still predominate in the non-Western world (i.e., Central and East Asia, South & Central America, and Africa). They already believe in many of the concepts that are present in Christian theology-God, sin, judgment, an afterlife, spiritual forces of good and evil, and the necessity of escaping judgment for the evil that we do. Biblically speaking, the best example of this type of person is Nicodemus ("A member of the Jewish ruling council"). Successful evangelism with a religious man like this involves building on what he already knows, but correcting his theology so that it reflects biblical truth. Books like The Strange on the Road to Emmaus and Peace Child reveal good methods for doing this. A Religious Man accepts revelation, respects tradition, uses reason, and values experience. All are valid pathways to truth to a religious man and all support his belief in a world that is ultimately spiritual.
- Scientific Man: These are the kind of people that began to rise in Europe beginning in about 1750 and in America about 1850. They dominated Western culture from about 1900 until around 1990. They find most of the Bible and anything supernatural unbelievable. For a scientific man, only what science can prove through empirical study (Can I touch, smell, see, hear, or taste it?) is true and real. The best biblical example of this type of person is Thomas ("Unless I see the nail marks in his hands and put my finger where the nails were, and put my hand into his side, I will not believe it."). Successful evangelism with a scientific man involves the presentation of evidence about such things as the general reliability of the Scriptures, the trustworthiness of the Gospels, the possibility of miracles, and the existence of God. A Scientific Man worships reason, disregards revelation, distrusts tradition, and evaluates experience by what seems to him to be rational. He believes reason is the valid pathway to truth, because his bedrock, pre-conversion belief is that the world is ultimately material.
- Hey Whatever, Man: These are the people that began rising in Europe in 1900 and in America about 1960. They are disillusioned by the world created by the "modernists" (i.e., Scientific Man), which though it enabled things like flight, cars, and vaccines, also created mustard gas, the atom bomb, and the Holocaust. As a result, they are very open to spiritual realities of whatever type (from palm reading to crystals, Hinduism to Christianity), but distrustful of any "institutional" or formal expressions of religious belief such as the Church. Since the scientific man's "objective truth" was so often used in support of causes that were evil, Hey Whatever, Man no longer believes that there is any such thing as objective truth (i.e., ideas that aren't dependent on the perspective of the person, but are true for everyone, everywhere). Instead, he believes that everything is "up for grabs" and that truth is completely individualized. The best biblical example of this type of person is Pontius Pilate ("What is truth?"). Successful evangelism with Hey Whatever, Man consists of giving him both information about the Christian faith and an experience of Christian truth as it is lived out in relationship with others. Hey Whatever, Man worships experience, distrusts reason, is intrigued by tradition, and is open to revelation. He believes that while the world is "kinda" material (i.e., he doesn't totally reject science), "there is more in heaven and earth than is dreamt of in your philosophy."
Obviously, most people are mixtures of one of the above, and no one fits these broad generalities perfectly anymore. But a good understanding of what "species" you are dealing with is critical for evangelistic success.