Romans 1:20 tells us that God’s invisible attributes, his eternal power and divine nature are clearly seen through what has been made (by him) so that all people are without excuse (for their sin). Because some in the history of Christian theology have used the term natural as a synonym for the physical creation, some have spoken of a natural theology—what people either can or do know about God through the physical creation. In the history of Christian theology there are fundamentally two ways in which this natural theology has been conceived.
The topics of apologetics and natural theology are, to say the least, complex and controversial. Yet as Christians we have to deal with them. So let us try informed by God’s word and the history of the Church.
We must define our terms, and while broad summary definitions can generally be agreed upon by those conversant with these topics, broad summary definitions are often of limited help. Still, we must start broadly while seeking specificity. The term theology comes from two Greek terms theos or God and logos or word, deed or word about, and so the term is broadly defined as the study of God or word about God. Some have argued that since the term itself is of Greek derivation the enterprise based upon it is corrupted at the outset with a non-Christian character. This argument commits what is called the genetic fallacy—thinking that the origin of a term or concept automatically discredits its use or eternally establishes its meaning. But words do not define themselves and previous definitions used by others do not bind us to define terms only in the previous ways they have been defined and used.
Christian apologetics is generally agreed to be the defense of the Christian faith and life. Our term “apologetics” is derived from the Greek term apologia, which can be defined as defense, reason or explanation. So, in this instance “defense” means a rationally coherent explanation that accurately expresses the truth of God’s written word. Thus, the standard for rationality is God as he has communicated himself through his word written. A number of truths are implied, rooted, or presupposed within the ability to give a rationally coherent explanation that accurately expresses God’s word.
This definition of apologetics implies that God effectively communicates some truth to all humans, that all humans have some capacity to understand and reason in accord with God’s truth or revelation, and that there is an unavoidable objectivity and subjectivity to reality and human reception and understanding of truth. By “objectivity” I mean that there is an aspect to reality that is what it is regardless of what anyone thinks or feels about it; it is the same for all people for all times and all places. By “subjectivity” I mean that there is an aspect to reality that is personal, and with respects to human knowledge it emphasizes the individual person’s experience with and perception of reality.