Here are standard objections and answers to them.
The essence of the replies is that the tri-personal God living in complete oneness is the best description of God, the Triunity—three persons contained within one God.
1.. Doesn’t this doctrine really come from later Church fathers?
This doctrine is developed by great theologians like Athanasius (c. 296-373AD) and Augustine (354-430 AD), but it was not invented by them. The New Testament was written to clarify pressing doctrinal and pastoral problems and issues that arose in the church.
Therefore, the New Testament authors, under the inspiration of the Holy Spirit, were not directed to develop the doctrine of the Trinity. Instead, they affirmed the full deity of Christ and the full deity and personhood of the Holy Spirit, but not in a formal doctrine.
Please see the post 2. Two Natures in One Person: He Was Human and God (numerous Scripture references)
See also The Personhood of the Spirit
2.. If there are three persons, why are there not three Gods?
The co-equal and distinct persons of the Father, the Son, and the Holy Spirit are not three Gods because they share the same essence in complete unity.
It is difficult for us humans to figure out because we do not share the same essence in unity.
For example, the patriarchs Abraham, Isaac, and Jacob are three distinct persons and beings. They do not share the same essence or being or divine attributes.
However, the doctrine of the Trinity says that the Father, the Son, and the Holy Spirit share the same being or essence, and this is where the human example of the three patriarchs and the divine nature must part company.
Thus, basic Christian doctrine teaches that one God exists in three persons: the Father, the Son, and the Holy Spirit, not in three Gods, which is called tritheism. Christians reject this doctrine.
3.. However, I read Christians writing, “God the Father, God the Son, and God the Holy Spirit.” Doesn’t that really say there are three Gods?
No, it is simply saying that the Father is fully divine (God), the Son is fully divine (God), and the Spirit is fully divine (God). Just because the same word God appears three times in one grammatical sentence does not mean there are three Gods. However, the persons of the Father, Son and Holy Spirit are three and distinct, expressed in three different words (Father, Son and Spirit!).
But the same and one word God simply indicates the same and one “Godness” of the three persons.
4.. Still, though, 1 + 1 + 1 = 3? So isn’t belief in the Trinity irrational?
Those digits can only refer to the three persons within the one being God; those numbers do not refer to his essence, which is one and unified.
Father + Son + Holy Spirit = Three Persons
Though I don’t like the numbers game, since the objector has taken us down the path of using numbers to refute the unity of God, let’s use them nonetheless, to clarify the simplistic addition model.
First, multiplication works better with integers:
1 x 1 x 1 = 1
In other words, three persons are united in one essence.
Second, the exponent comes out the same:
13 = 1
The conclusion is the same: Three persons are united in one essence.
Third, how about an infinite number of sets of things? This works better:
Infinity + infinity + infinity = infinity.
It works out like this:
Infinite God the Father + Infinite God the Son + Infinite God the Spirit = Infinite One God
Three infinite persons are united in one infinite being called God, not infinite Gods (plural).
Let’s say that we add an infinite number of red books to an infinite number of white books, and still add an infinite number of blue books to the red and white books. Despite adding these three sets of infinite numbers of books together, we have not augmented or increased infinity by even one book. Such is the mystery of infinity; we cannot figure it out.
However, these three mathematical analogies of the Trinity ultimately fail because, among other reasons, the three infinite sets of books have different properties, because they do not exist in perfect unity in one essence, and because we do not “add up” or even “multiply” the three living persons of the Trinity.
Numbers ≠ Persons
So the numbers game fails.
Nonetheless it is now clear that belief in the Trinity is not irrational, but transrational — above our puny minds to figure out, ultimately.
5.. Is God divided up into thirds?
To clarify further why there are three persons, but not three Gods, God’s essence is not divided equally into three parts; it is not one-third, plus one-third, plus one-third. Also, the three persons are not added on to God’s essence or being, as if they are tacked on to the outside of God. Rather, all three persons share the same essence, fully God in one being, in total and perfect unity. Thus, basic Christian doctrine teaches that one God exists in three persons: the Father, the Son, and the Holy Spirit
6.. Doesn’t the doctrine of the Trinity entail contradictions?
Mysteries are not contradictions. Here are two examples of contradictions:
There is one God and there is not one God;
God is three persons and God is not three persons.
But the claim that the one God exists in three persons who possess the same divine essence in perfect unity does not entail a contradiction (Grudem p. 256).
There is no contradiction in having three persons in one essence, for the terms are different. God is one and only one in relation to his essence, and God is three in relation to his persons. These two relations are two different senses (Geisler p. 550).
The Trinity ultimately is a mystery, but it is revealed in Scripture, so all Bible-educated and Bible-believing Christians believe in it, even though they may not understand it fully.
7.. Doesn’t the doctrine of the Trinity ultimately come from pagan myths?
The doctrine of the Trinity, if properly understood, is found nowhere in mythology – not even close. Zeus, Poseidon, and Apollo and any other trio of gods from around the Greek and Roman world do not share all of the same attributes in perfect unity as one God. In fact, Greek myths go out of their way to keep these gods distinct as three gods and beings with their own special attributes. The Trinity has nothing to do with a family or pantheon of squabbling gods or separate divine beings.
This is polytheism, and Christians reject it.
8.. Isn’t the Islamic belief in a single, one-person deity the simplest and best way to go?
Islam (and Judaism) teaches strict monotheism, like so:
1 = 1.
At first glance that does appear simple and therefore the best option.
However, some Muslim sects believe the Quran is eternal and uncreated, and this poses problems for strict monotheism. But let’s set this issue aside.
Problems still emerge relationally.
1 = Lonely, isolated Allah
What was this Islamic deity doing all by himself in eternity past, before he made the heavens and the earth and the angels?
Louis Berkoff says this about isolated personalities, whether God or human:
Personality does not develop or exist in isolation, but only in association with other persons. Hence it is not possible to conceive of personality in God apart from an association of equal persons in Him. His contact with His creatures would not account for His personality any more than man’s contact with the animals would explain his personality. In virtue of the tri-personal existence of God there is an infinite fulness of divine life in Him. (pp. 84-85, emphasis original)
In other words, an isolated deity would have a deficient and short-changed personality. This is especially clear when we read in Scripture that humans are created in his image (Gen. 1:26-27). “It is not good for man to be alone” (Gen. 2:18). So living alone in isolation is not optimal for humans. Now what about God? No, we shouldn’t raise man up to the level of God, “but rather what appears as imperfect in man exists in infinite perfection in God” (Berkoff p. 84). God is not needy, but the living God existing in three persons is optimal, not a single-personal deity existing in lonely isolation.
9.. Why didn’t Jesus and Paul just sit down and offer an extended teaching on the Trinity?
Let’s look at the beginning.
Deut. 6:4 offers the famous shema: “Hear, O Israel, the LORD our God is one.” The Hebrew word for God is Elohim, and the -im ending indicates masculine plural. So it works out like this: Elohim (plurality) is one (unity). Plurality in unity is a perfect, boiled-down, beginning statement of the Triunity of God: Father, Son and Holy Spirit contained within one God. Forgive the analogy, but picture three pearls within one cup.
Jesus repeats this phrase in Mark 12:29: “The Lord our God is one,” and Paul does the same in Gal. 3:20: “God is one.” Jesus said affirmation that in a Jewish context, and Paul in a polytheistic context. It makes since that Jesus would wish to reach out to his fellow Jews, and Paul would wish to lead pagans away from their distorted view of the divine world.
Jesus did not even want some people to whom he ministered to know that he was the Messiah, by a formal announcement (Matt. 8:4; 12:16 // Mark 3:12; 7:36; 11:33 // Luke 5:34; 8:56). Even Peter had to receive special revelation to affirm that Jesus was the Messiah (Matt. 16:16; // Mark 8:29 // Luke 9:20). How much more would it have been difficult for the earliest Jews to accept his higher status, as God in the flesh? Also, the Gospel of John does show Jesus in his fullness (John 1:1-3; 8:58). Jesus said “I and the Father are one” (John 10:30). That looks like a variation on the shema. And people found it difficult to accept, but his claims were true, nonetheless.
Paul writes that God was pleased have all his fullness dwell in Jesus (Col. 1:19) and the fullness of deity dwelled in bodily form (Col. 2:9). In Tit. 2:13 Paul says the church is eagerly waiting for the appearing or the great God and Savior, Jesus Christ. There are other such passages.
See the post in this Christology series:
2. Two Natures in One Person: He Was Human and God (numerous Scriptures)
Bottom line: Jesus and Paul had a more practical objective: proclaim the kingdom of God and salvation and solve church problems.
Fortunately, Scripture affirms that God lives in a tri-personal community in perfect love and unity. “God is love” (1 John 4:8 and 16).
So how does knowing about the Trinity help me know God better?
There is an entire ten-point post that answers that question, here:
Written by James Malcolm
ARTICLES IN THE TRIUNITY SERIES
The Trinity: What Are Replies to Objections?