Many interpreters believe that John 14:2-3 teaches the Second Coming or rapture before the Second Coming, but 14:23 decisively argues against this interpretation.
The Greek is straightforward, and here is my translation. You are encouraged to view other translations at biblegateway.com:
“In my Father’s house there are many rooms [monai; plural here]; if it were otherwise, would I have told you that I go to prepare a place for you? If I go to prepare a place for you, I am coming again and shall receive you to myself, so that where I am, you may also be.” … In reply Jesus told him [Judas, not Iscariot], “If anyone loves me, he will keep my word, and the Father will love him, and we will come to him and make a room [monē; singular here] for him.” (John 14:2-3, 23)
The Greek noun monē (pronounced moh-nay) is an extremely rare word, and it means “dwelling(-place), room, abode” (so says BDAG, considered by many to be the authoritative lexicon of the Greek NT). It can be used in a spiritual sense. The KJV translated it as “mansion,” after the Latin, but this term is misleading for English speakers. We need to interpret the Greek term by only one other appearance in the entire NT (v. 23).
And v. 23 argues against 14:2-3 being properly interpreted as the Second Coming or a rapture before the Second Coming, because the Father and the Son will come and make a room or dwelling-place or abode for the disciple. In contrast, the doctrine of the Second Coming or separate rapture says that the Father does not come back; the Son does.
In John 14 nowhere does Jesus say the last day in the chapter, as he did in John 6:39, 40, 44, 54. And John 5:28-29 says “an hour” that is coming, but this is about the final resurrection and the final judgment. Also John 11:24 says that the resurrection happens on the last day. Those verses are about the Second Coming and unrealized eschatology (still unfulfilled until the last day).
For other important verses about the last day and the Second Coming, please click on this post:
John 14, in contrast, is about Jesus going away at his resurrection and ascension and not leaving his disciples (then and now) as orphans, but the Father and Son will come to them through the Spirit, who will live in them (vv. 17-18). Only by the Spirit’s coming can we do greater works than Jesus did (v. 12), after he goes to the Father (= resurrection and ascension).
It is true that Jesus says “on that day” (v. 20), but clearly this time marker is still about the resurrection and ascension and the coming of the Spirit (v. 19) because Jesus is in the Father, and “you are in me and I am also in you.” Only the Spirit can create this kind of unity and intimacy. The world will not see him before long, but the disciples will see him (again the resurrection and ascension). And he intends to show himself to the disciples but not to the world (v. 22). As it turned out, the disciples saw him in his resurrected state, but the world did not. The world has not received the Spirit, but the disciples have.
The Father and the Son come and make a room monē for the disciple (v. 23) in the Father’s house (v. 2). Further, v. 26 speaks of the Father sending the Holy Spirit. The coming of the Spirit, which happened in John 20:21-22, and the Second Coming do not go together but are now separated by two thousand years (and counting).
Therefore, the main point of John 14 is that the Father and Son send the Holy Spirit and through him they prepare rooms for Jesus’s disciples, if they love him and keep his word or teaching. John 14 is not a teaching on the Second Coming or separate rapture.
So what is the room? It is probably a room in the new temple (= the church) (cf. John 2:19-21). John 14:2 says “in my Father’s house.” This likely refers to the church / temple. The church being the new temple is a clear teaching of the New Testament. Please see this post for many quoted references:
And no, this is not “replacement theology” in the standard meaning of the term, which says the church replaces Israel. At that link, the church replaces the temple.
All of this is to say, once again, that John 14 is about the coming of the Father and Son through the Spirit who brings us intimacy with the Father and the Son and each other. Only the Spirit can link us all up in heaven and earth at the same time and provide such intimacy. The room is this intimate belonging to the Father’s house–to the Father and Son by the Holy Spirit and collectively in the church.
Luke 21:5-33 Predicts Destruction of Jerusalem and Temple (Luke is by far the clearest on this topic)