John 10:30 (KJV) is often quoted to support the doctrine of the Trinity:

30 I and my Father are one.

But during the great intercessory prayer, Christ asks God for his disciples to also be one with them:

John 17:20-21 (KJV)

20 Neither pray I for these alone, but for them also which shall believe on me through their word;
21 That they all may be one; as thou, Father, art in me, and I in thee, that they also may be one in us: that the world may believe that thou hast sent me.

Non-trinitarians often quote that scripture to show how John 10:30 (and other scriptures like it) is being misinterpreted. They say, "If God and Christ are literally one, then is Christ praying for us to become part of their nature too?"

Tons has been written about the Trinity, so surely a reasonable explanation for this exists.

How can John 17:20-21 be reconciled with the doctrine of the Trinity?


3 Answers 3


The fundamental thing you have to remember about the Trinity is that God is both One and Three. It's really easy to find quotes that support Jesus and the Father as separate, and the response of the Christian is "yes, they are". It's also really easy to find verses that completely support the idea that God is One, and that Jesus is God. And the response of the Christian is "yes, they are". It is precisely the combination of those that gave rise to the doctrine of the Trinity.

A good reference for this is the Athenasian Creed:

The Father Uncreate, the Son Uncreate, and the Holy Ghost Uncreate. The Father Incomprehensible, the Son Incomprehensible, and the Holy Ghost Incomprehensible. The Father Eternal, the Son Eternal, and the Holy Ghost Etneral and yet they are not Three Eternals but One Eternal. As also there are not Three Uncreated, nor Three Incomprehensibles, but One Uncreated, and One Uncomprehensible.

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    Be careful: Trinitarianism says that God is three persons in one divine essence. Simply saying that God is one and three at the same time, without further explanation, borders on logical contradiction.
    – gmoothart
    Oct 22, 2011 at 21:49
  • I agree with gmoothart. Trinitarianism will never accept such thing as God is Three!
    – deps_stats
    Oct 22, 2011 at 22:54
  • I refer you to the creed of Athenasius. Oct 23, 2011 at 15:58
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    I quote the creed of Athanasius: That we worship one God in Trinity, and Trinity in Unity [...] As also there are not three uncreated; nor three infinites, but one uncreated; and one infinite. [...] And yet they are not three Almighties; but one Almighty. [...] And yet they are not three Gods; but one God. [...] And yet not three Lords; but one Lord. For like as we are compelled by the Christian verity; to acknowledge every Person by himself to be God and Lord; So are we forbidden by the Catholic Religion; to say, There are three Gods, or three Lords.
    – deps_stats
    Oct 24, 2011 at 2:28
  • My point exactly. Oct 24, 2011 at 13:21

As this question is tagged as catholic. I think I'll approach the catholic view (which certainly relates to all Trinitarian churches) but I will also bring up some doctrine of the eastern orthodox churches.

As Caleb puts it, this question is related with the Biblical basis for the doctrine of Trinity. Byrd and Software monkey answered outstandingly. The answers should be reviewed prior to this answer. Certainly there is a similarity amongst the questions, but JustinY's question seems to be more concerned with the relation that exists between Father, Son and Holy Spirit.

The core of the question relies in the following:

  1. That they all may be one; as thou, Father, art in me, and I in thee
  2. That they also may be one in us

To answer the first point it is important to bring back the doctrine of Trinity that explains that there is One God in three persons(ὑποστάσεις), with the same substance(οὐσία). To explain the difference between hypostasis and ousia is clearly stated by Basil of Caesare:

[...] ousia has the same relation to hypostasis as the common has to the particular. Every one of us both shares in existence by the common term of ousia, and, by his properties, is such an one and such an one. In the same manner...the term ousia is common, like goodness, or Godhead, or any similar attribute, while hypostasis is contemplated in the property of Fatherhood, Sonship or the power of Sanctification. St. Basil, Basil: Letters and Select Works. Quoted in The Trinitarian Theology of St. Basil of Caesare by John Behr

Father and Son are the same ousia. Jesus himself teaches that there is One God in Mark 12: 28-31.

The second part of the question is how are the faithful are one in Christ. The answer may be found in John 15:4-5:

Remain in me, as I also remain in you. No branch can bear fruit by itself; it must remain in the vine. Neither can you bear fruit unless you remain in me. “I am the vine; you are the branches. If you remain in me and I in you, you will bear much fruit; apart from me you can do nothing. (NIV)

And may be expanded by recalling that the church is the body of Christ (1 Corinthians 12: 12-31) and it is Spouse of Christ.

To support this point one may use the following verse:

Now you are the body of Christ, and each one of you is a part of it. (NIV 1 Corinthians 12: 27)

and also de article 796 of the Catechism of Catholic Church, of which I extract one excellent quote of St. Agustine:

This is the whole Christ, head and body, one formed from many . . . whether the head or members speak, it is Christ who speaks. He speaks in his role as the head (ex persona capitis) and in his role as body (ex persona corporis). What does this mean? "The two will become one flesh. This is a great mystery, and I am applying it to Christ and the Church."240 and the Lord himself says in the Gospel: "So they are no longer two, but one flesh."241 They are, in fact, two different persons, yet they are one in the conjugal union, . . . as head, he calls himself the bridegroom, as body, he calls himself "bride". (St. Agustine. Enarratio in Psalmum 74, 4)

In few words, it is explained that the Church and Christ are one in a similar way in which husband and wife are one flesh. Because the Church is the wife that Christ loved for whom he gave himself up (Ephesians 5:25).

Hope this answers your question.


It really can't be. Everything we have about Jesus's interactions with the Father shows them as separate, distinct beings. Even the example given here, John 10:30, describes them as distinct; it just gets lost in translation. In the original manuscripts, the word "one" used here means "united," just like you would describe a group of people today working together with the same purpose as being "one" or "as one." Saying that they are literally the same would be a different word.

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    This doesn't satisfy. The root word in the original seems to be εἷς which is quite literally the numeral 1. It's translated 'a', 'one', 'single' and other variations of 'one'. In context it seems to read pretty much like the English does. "I and the Father are one." If it doesn't literally mean one unit in this text, it's going to take a more full explanation of why not. (I agree this is probably not a good proof text for the Trinity, but this answer leaves me wondering why.)
    – Caleb
    Sep 11, 2011 at 18:48
  • @Caleb: Here's the explanation I heard. The root, as you mentioned, is the number 1. But there are different ways of expressing the number. English doesn't have gender-forms for nouns in general, but Greek does. The 1 used here is the neutral-gender 1, which connotes unity in this context. Establishing a single identity would require a masculine 1, not a neutral 1.
    – Mason Wheeler
    Sep 11, 2011 at 19:03
  • Note: I don't actually speak Greek, though I do speak Spanish, which uses gendered nouns, and so the concepts involved make sense to me. If any native Greek speakers could elaborate on this, their input would be welcomed.
    – Mason Wheeler
    Sep 11, 2011 at 19:08
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    I don't speak Greek either, in that area I'm just a hacker. But I've been doing some research on this verse and contrary to my initial guess it seems there is quite a bit of evidence for this actually being an echo of "The Lord is One" in Deut. 6:4 and would have been understood by the Jews as a claim to divinity -- and hence in our understanding part of the Trinity.
    – Caleb
    Sep 11, 2011 at 19:54
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    The Greek is hen esmen. The word is primarily used to indicate "alone", "one thing", or "one". Only thrice out of over 300 uses is it translated (in NASB) as "agreement", "unity", or "common". Theres a very strong case that this means a single, cardinal number.
    – Richard
    Sep 12, 2011 at 12:36

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