A little over a year ago, there was great discussion over the question of whether Christians and Muslims worship the same God. The nuances of this debate are beyond this blog post (and let’s be honest, probably beyond any single blog post of around 1,000 words!), but in those discussions, one of the points that I would always return to is that this claim should be insulting to both Christians and Muslims, as one of the fundamentals of the Christian belief system is that God is Triune — eternally existing in three persons, as discussed in the last post — while this claim is flatly, explicitly, and forcefully denied by Muslims. The nature of God and the person of Jesus is a significant dividing line between Muslims and Christians. This might raise the question of why Christians believe in the doctrine of the Trinity, as this doctrine, if we are honest, can be confusing and is pretty mysterious. Article 9 of the Belgic Confessions gives us two reasons why Christians believe in the Trinity: “from the testimonies of Holy Scripture as well as from the effects of the persons, especially from those we feel within ourselves.” In sum: the Bible and our experiences.

First, we believe in the Trinity because of what we find in the Bible. It is true that the word “Trinity” never appears in the Bible, but throughout it we see the teaching emerge that God is not a singular being but Triune; there is one God who exists in three persons. The Belgic Confession goes through some of these passages but also notes that it cannot examine every one of them: “The testimonies of the Holy Scriptures, which teach us to believe in this Holy Trinity, are written in many places of the Old Testament, which need not be enumerated but only chosen with discretion.” My paraphrase: there are many places but we will just look at a few. The first one that the Confession looks at is Genesis 1:26: “ Then God said, ‘Let us make man in our image, after our likeness.’” Why the use of the plural [us]? Some writers will argue that God is speaking to the angels, but this does not make sense of the fact that God is different from the angels — we are not made in the image of angels. Others will argue that this plural is a “Plural of majesty,” in which to show dignity one uses “we” instead of “I.” This is possible, but does not seem the best explanation. It is true that this verse does not explicitly state that God is plural – and the Confession notes that it does not state that God is three – but when this passage is combined with the rest of Scripture, it hints at the doctrine of the Trinity. When one reads that there is a plurality (our image) but later a singularity (God created – just one), it points to the fact that God is more complex.

When one turns to the New Testament, this idea of God being plural and this plurality being the number three becomes more clear. Perhaps the best place to turn is Jesus’s baptism, which can be found in Matthew 3:16-17 (in addition to the parallels in the other gospels). Here, we see a voice (the Father) speaking about Jesus (His Son), with the Holy Spirit descending as well. All three persons exist together and are distinguished; this passage refutes the idea that some people have taught (falsely) and that some well-meaning Christian will inadvertently teach: that God is like water in that he can takes three different forms at different times. This is modalism (what is called Sabellius in the Confession after one of the teachers) and one that is rejected by the ecumencial creeds (ones adopted by Christians everywhere) – the Apostles’ Creed, the Nicene Creed, and the Athanasian Creed – and by Christians through the ages.

There are other passages in the New Testament which reveal to us the doctrine of the Trinity. The Great Commission in Matthew 28:19-20 speaks about baptizing people in the name of the Father, the Son, and the Holy Spirit, pointing to all three persons being equal and in connection with each other. Paul’s concluding blessing in 2 Corinthians 13:14 (with which I often close a service) speaks about the grace of the Lord Jesus, the love of the Father, and the fellowship of the Holy Spirit — once again putting these three persons in a status of equals. The Belgic Confession also cites 1 John 5:7 that speaks about the Father, Son, and Holy Spirit bearing witness in heaven and that these three are one. One will find this verse in the old King James Bible and in the New King James but not in most modern translations (ESV, NIV, etc.) because this verse is not found in the oldest and the best manuscripts that we have of the New Testament (perhaps a future post will deal with issues and questions of textual criticism and why we have missing verses like this, as it is complicated but also fascinating at least to me!). Saying that this verse is not likely in the original writing, however, does not undercut belief in the Trinity because of the other verses that are noted; moreover, this variant reading shows that Christians believed this truth even in early times.

As the Confession therefore notes, “In all these passages we are fully taught that there are three persons in the one and only divine essence. And although this doctrine surpasses human understanding, we nevertheless believe it now, through the Word, waiting to know and enjoy it fully in heaven.” I love this statement, as it reminds us that there is mystery in this doctrine and that it surpasses our understanding in how it exactly works but that we believe it and will fully know it in the future.

However, we also want to look at the second reason that that Confession gives us for belief in the Trinity, which is our experience of this truth. Here is how the Confession puts it: “Furthermore, we must note the particular works and activities of these three persons in relation to us. The Father is called our Creator, by reason of his power. The Son is our Savior and Redeemer, by his blood. The Holy Spirit is our Sanctifier, by his living in our hearts.” We believe the Trinity because it shows us the gospel, with God creating and guiding, the Son redeeming, and the Spirit applying salvation to our hearts and working in our lives to make us like Christ. The doctrine of the whole Spirit cannot be fully understood but it should be experienced as we are saved.

The Trinity is a doctrine that does not divide Christians but rather divides Christians from other groups. The early Christian leaders spent a lot of time thinking and writing about this doctrine because it is a doctrine upon which our salvation is dependent and the gospel is taught and made real.

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