Why is Heaven Forever?

God the Father 

First, the Scriptures consistently portray redemptive history in terms of a husband seeking his bride. God's people are united to their husband, Christ, by faith. This indissoluble union begins when we place our faith in the one who is "chief among ten thousand." A significant implication emerges from this truth: Heaven is eternal because we are married to Christ, and God hates divorce. God would first have to sin by dissolving our union with Christ before Heaven could end. When God sins in this manner then Heaven will end. 

Second, there shall be no desire from us in heaven to look anywhere else but at Christ. As John Owen says, our vision of the God-man in heaven will be "immediate, direct...and therefore steady, even, and constant." Christ's personal glory will always be before us: "As a man sees his neighbour when they stand and converse together face to face, so shall we see the Lord Christ in his glory." 

We sin in this life when we do not fix our eyes on Jesus. The man looking at internet pornography has taken his eyes off Jesus for a pitiful and pathetic substitute. But in heaven our eyes will never be diverted from beholding the glory of Christ in a manner "a thousand times above what here we can conceive" (Owen).

Third, our glorious resurrected bodies are temples of the Holy Spirit. If this is true in this life, how much more in the life to come? The Holy Spirit, who is Christ's Spirit, makes us able to bear Christ in his majesty. The Holy Spirit enables God's people in Heaven to receive communications from God through Christ that we on Earth could not bear right now. His goal is Christ's goal: the eternal satisfaction of Christ and his people viewing one another with delight. Since love is a fruit of the Spirit, our love for Christ will be the reason why we shall always desire to behold the king in his beauty. Moreover, the Spirit would have to pass out of existence for us to pass out of existence, such is the nature of his indwelling.