Jesus promises there will be room for believers in his Father's house. This is where we will spend eternity with Jesus.
The Parable of the Father's House
These words fit into the symbolism of an end-time wedding between Christ and his Church. According to this, the disciples represent the bride to whom Jesus is making a proposal of marriage. At some point in the future, Jesus will return as the bridegroom to claim his bride, the wedding feast will take place, and the bride will live with him in his Father's house. According to Jewish custom, after a man made such a proposal he would drink from a glass of wine and pass it to the bride. If she then drank from it, she demonstrated her acceptance of his proposal, and the marriage covenant was confirmed. On the same night that Jesus spoke these words, Luke 22:20 records, "And in the same way he took the cup after they had eaten, saying, “This cup that is poured out for you is the new covenant in my blood". After acceptance of such a proposal, it was normal that the bridegroom would go away to make preparations for the wedding, and to prepare a place in his Father's house where they would live. In practical terms, that might have meant building an extension, or another floor to his father's house.

Jesus assures us there are many dwelling places in his Father's house (v2). In other words, there is room for him to accommodate the Church, however large.

Interpreting this parable in practical terms raises several questions that do not necessarily have clear answers in scripture:

1) Where is the Father's house located, in the present heaven or in the New Heaven?
The Father's house represents where we will spend eternity with Jesus after the wedding. It is located in the New Jerusalem, which is called the bride (Revelation 21:9). The word 'bride' denotes both the city and those who will live there. Similarly, we use the word 'church' to denote both a building and its occupants. The New Jerusalem is the New Heaven.

2) In the present age, where do believers go when they die?
Philippians 1:23 indicates that Christian believers go directly to be with Jesus when they die. I assume this to be in the present heaven which will pass away after the New Heaven is revealed (Revelation 21:1). Presumably the Father has a house in the present heaven, but he will have a new house in the New Heaven.

3) Where will Christian believers live in the Millennium?
The Millennium is a period of overlap between the present age and the eternal age. During the Millennium, Jesus will live on Earth in Millennial Jerusalem. Revelation 20:4-6 indicates that some, but not all believers will reign with him on Millennial Earth. Presumably the rest remain in heaven. Whether they move from the present heaven to the New Jerusalem at the beginning or end of the Millennium is not made clear. The wedding feast takes place near the beginning of the Millennium (Revelation 19:6-10), but the New Jerusalem does not descend to Earth until the end of the Millennium (Revelation 21:10). It is as though the wedding occurs in stages at both beginning and end of the Millennium.

In verse 3, Jesus says, "And if I go and make ready a place for you, I will come again and take you to be with me, so that where I am you may be too". Logically, this implies that we must understand Jesus to be present both on Earth and in Heaven during the Millennium. Otherwise, if Jesus is on Earth and some believers are in Heaven during the Millennium, then the second coming separates them from Jesus rather than uniting them with him. The Parable of the Father's House will ultimately be fulfilled at the end of the Millennium, from which time all believers will live with Jesus in his Father's house forever.
Places: New Jerusalem
Symbols: Wedding, House, Bride of Christ, Bride
Tags: Life after death, Millennium, End-time bride
Jesus’ Parting Words to His Disciples
14 “Do not let your hearts be distressed. You believe in God; believe also in me.
2 There are many dwelling places in my Father’s house. Otherwise, I would have told you, because I am going away to make ready a place for you.
3 And if I go and make ready a place for you, I will come again and take you to be with me, so that where I am you may be too.
4 And you know the way where I am going.”
5 Thomas said, “Lord, we don’t know where you are going. How can we know the way?”
6 Jesus replied, “I am the way, and the truth, and the life. No one comes to the Father except through me.
7 If you have known me, you will know my Father too. And from now on you do know him and have seen him.”