From “Ask Pastor John”, a question and answer series by John Piper:
It is certainly not peripheral, and it shouldn’t be the only thing we study. I’m putting myself in the middle here. I think it is an absolutely essential doctrine that Christ fulfill God’s purposes for this universe–and this world in particular.
It is essential that Jesus come back in the flesh and that he triumph with finality over the devil and over all evil. He must banish all ungodliness and establish his kingdom. He must bring a new heaven and a new earth, so that there is only righteousness and peace. And that everything that God has designed for this world must come to its climax.
If we said that Christ didn’t have to come back, and that all we had was a perpetual state of what we have now, it would be a tragedy. The Bible would abort and God’s purposes would not stand.
So the redemption of our lives is not complete until we have, as it says in Romans 8:32, our “adoption as sons, the redemption of our bodies.” And the redemption of our bodies happens, according to Philippians 3:21, when the Lord of glory comes back in his glorious body and gives us bodies like his glorious body. This will happen at the second coming, and so it is an absolutely essential doctrine.
But if you get fixated on all the details of when and how the second coming will take place then you will probably become sectarian in your attitudes and behaviors–and in your church. Glorious things about the past and the present, and the way God works now, and how we should relate to culture now threaten to be obscured or lost altogether.
So don’t let the second coming of Christ and its surrounding events become the totality of what you focus on. Let it be the end-time hope that satisfies your heart, and then give yourself to a full-orbed understanding of all the Bible. Consider its application to family and business and culture and leisure and entertainment and education and all the aspects of life now in which we’re called to be salt and light.