Answer
Natural religion is an approach to God that dispenses with the need for miracles, sacred texts, or supernatural concepts, relying instead on human reason and experience. It is “natural” religion as opposed to “supernatural” religion. Natural religion, or natural theology, seeks to know God through rational analysis, approaching theology as a scientific endeavor to be explored through reason and the five senses.
There are three ways in which God has revealed Himself, but natural religion only accepts the reality of one. The first way God has revealed Himself is called ontological revelation, which involves God becoming human in Jesus: “God, who said, ‘Let light shine out of darkness,’ made his light shine in our hearts to give us the light of the knowledge of God’s glory displayed in the face of Christ” (2 Corinthians 4:6).
The second method of God’s revelation is termed special revelation and is represented by the Bible, which delivers God’s message of salvation and more to the world: “All Scripture is God-breathed and is useful for teaching, rebuking, correcting and training in righteousness, so that the servant of God a may be thoroughly equipped for every good work” (2 Timothy 3:16–17).
The third mode of revelation is labeled general revelation, in which God reveals Himself in creation, along with the effects He has produced. Of general revelation, Thomas Aquinas wrote, “From every effect the existence of its proper cause can be demonstrated. . . . If the effect exists, the cause must pre-exist. Hence the existence of God . . . can be demonstrated from those of His effects which are known to us” (from Summa Theologiae I, Article 2). It is general revelation that is the sole basis for natural theology.
David speaks of the value of general revelation when he writes, “The heavens declare the glory of God; the skies proclaim the work of his hands. Day after day they pour forth speech; night after night they reveal knowledge. They have no speech, they use no words; no sound is heard from them” (Psalm 19:1–3).
The apostle Paul states that, on the basis of natural theology, everyone can know of the existence and power of God: “That which is known about God is evident within them; for God made it evident to them. For since the creation of the world His invisible attributes, His eternal power and divine nature, have been clearly seen, being understood through what has been made, so that they are without excuse” (Romans 1:19–20, NASB, emphasis added).
Because an effect must resemble its cause, and a cause can only give what it already possesses, a person “clearly sees” God’s “invisible attributes” by observing creation and reasoning back to the Creator. Natural theology, based on reason and observation, argues that whatever brought everything into existence must possess the following attributes:
Supernatural (because it created the natural) — Genesis 1:1
Powerful (incredibly) — Jeremiah 32:17
Eternal or self-existent — Psalm 90:2
Omnipresent (it created space and is not limited by it) — Psalm 139:7
Timeless and changeless (because it created time) — Malachi 3:6
Immaterial (because it transcends space/physical) — John 5:24
Purposeful/personal (defined as “having intent”) — Genesis 3:9; Jeremiah 29:11
Necessary (as everything else depends on it) — Colossians 1:17
Infinite and singular as you cannot have two infinites — Jeremiah 23:24; Deuteronomy 6:4
Diverse yet unified (as unity in diversity exists) — Matthew 28:19
Intelligent (supremely) — Psalm 147:4–5
Moral (moral laws require a moral lawgiver) — Daniel 9:14
Caring (or no moral laws would have been given) — 1 Peter 5:6–7
Of course, natural theology dismisses the need for biblical support, but we have provided it here to show that an objective critique of general revelation will lead to conclusions congruent with God’s special revelation. Far from being a “God of the gaps” argument, natural theology attempts to use reason, logic, and more to determine the cause (God) ultimately behind everything that exists. Natural religion, so far as it goes, can be helpful in apologetics; however, mankind will never “reason” their way to salvation. We need God’s special revelation and the work of the Holy Spirit for that.