The doctrine of the Trinity is grounded in several explicit teachings of Scripture. First, according to Scripture, there is one, and only one, God. We read, for example, in Deuteronomy 4:35, “To you it was shown, that you might know that the Lord is God; there is no other besides him.” Second, Scripture affirms that the Father is God. Jesus often speaks of “God the Father” (e.g., John 6:27). Paul speaks numerous times of “God our Father” and “God the Father” (e.g., Rom. 1:7; 1 Cor. 1:3).
Third, Scripture also affirms that the Son is God. In the prologue to the gospel of John, the “Word,” who is revealed to be Jesus (1:14), is identified as God (v. 1). Fourth, Scripture affirms that the Holy Spirit is God. He is equated with God in Acts 5:3–4. Elsewhere, the New Testament authors identify the Holy Spirit with Yahweh through their use of Old Testament quotations. Compare, for instance, Isaiah 6:8–10 with Acts 28:25–27 and Psalm 95:7–11 with Hebrews 3:7–11. Fifth and finally, although the Father, Son, and Holy Spirit are affirmed to be God, Scripture also distinguishes the three. They are distinguished, for example, by use of the language of sending, loving, speaking, interceding, etc. (see Luke 3:22; John 3:16–17; 3:35; 11:41–42; 14:15; 15:26; Rom. 8:26–27).
The biblical doctrine of the Trinity is summarized in the Nicene Creed:
I believe in one God, the Father Almighty, Maker of heaven and earth, and of all things visible and invisible.
And in one Lord Jesus Christ, the only-begotten Son of God, begotten of the Father before all worlds; God of God, Light of Light, very God of very God; begotten, not made, being of one substance with the Father, by whom all things were made. Who, for us men and for our salvation, came down from heaven, and was incarnate by the Holy Spirit of the virgin Mary, and was made man; and was crucified also for us under Pontius Pilate; He suffered and was buried; and the third day He rose again, according to the Scriptures; and ascended into heaven, and sitteth on the right hand of the Father; and He shall come again, with glory, to judge the living and the dead; whose kingdom shall have no end.
And I believe in the Holy Spirit, the Lord and Giver of life; who proceedeth from the Father and the Son; who with the Father and the Son together is worshipped and glorified; who spake by the prophets.
The doctrine of the Trinity is fundamental to the Christian faith. If any element of it is rejected or altered, every other Christian doctrine is negatively affected.
3. God accepts the worship of all religions, including Christianity, Judaism, and Islam.
In the contemporary world, it is common for people who believe in God to affirm that God accepts the worship of all religions as long as the worshiper is sincere. There is no evidence for such a view in Scripture, however. In fact, from Genesis to Revelation, Scripture reveals the exact opposite.
This is clearly seen in the first of the Ten Commandments: “You shall have no other gods before me” (Ex. 20:2). The ancient Near Eastern world in which Israel lived was filled with all manner of religions and “gods.” God rejects these other religions. Why? Because the “gods” of these other religions are actually demons, and the worship of these demons is an abomination (Deut. 32:16–17; Lev. 17:7). The Apostle Paul teaches the same in the New Testament (1 Cor. 10:20).
During His temptation, Jesus quotes Deuteronomy 6:13 to Satan, saying, “You shall worship the Lord your God and him only shall you serve” (Matt. 4:10). That is religious exclusivism. In the incarnation, the Word who was with God and who was God became flesh and dwelt among us (John 1:1, 14). He is now the one mediator between God and men (1 Tim. 2:5). There is no other.
Jesus Himself clearly expressed the exclusivity of Christianity when He said: “I am the way, and the truth, and the life. No one comes to the Father except through me” (John 14:6). “No one” means no one. This is why Peter, when filled with the Holy Spirit, proclaimed the following regarding Jesus: “There is salvation in no one else, for there is no other name under heaven given among men by which we must be saved” (Acts 4:12). For those seeking salvation, there is no one else.
If God accepted the worship of all religions, there would have been no need for the incarnation, death, and resurrection of Christ because there were plenty of existing religions already during the first century. If God accepted the worship of all religions, there would also have been no need for the Great Commission and the evangelization of the nations. If God accepts the worship of all religions, the evangelism that Jesus commanded is a waste of time.
God does not accept any religion other than the one He graciously provided. He does not accept religions that substitute worship of the creature for worship of the Creator. God does not accept false worship. God does, however, accept the worshipers of any religion when they repent of those religions and trust in Christ.
4. God created male and female.
A fundamental aspect of human nature is that human beings are male and female. This is the case because God created human beings as male and female: “So God created man in his own image, in the image of God he created him; male and female he created them” (Gen. 1:27). The same truth is repeated a few chapters later: “When God created man, he made him in the likeness of God. Male and female he created them, and he blessed them and named them Man when they were created” (5:1–2). Jesus refers back to this basic fact of creation when the Pharisees pose a question about divorce. He begins His response by saying, “Have you not read that he who created them from the beginning made them male and female?” (Matt. 19:4).
Nature teaches this same truth, as any student of biology knows. There are noticeable physical differences between males and females due to the way God created the human reproductive system. Every other system in the human body can fully function in a single human body. The digestive system, the respiratory system, the circulatory system, the immune system, etc., can all fully function in an isolated single human being. The reproductive system, on the other hand, requires a male and a female to fully function and to actually reproduce human beings. Because of the fall, birth defects and other abnormalities in the reproductive system sometimes occur, but we recognize these as abnormalities only because we clearly know what the normal reproductive system is.