If we die and go to heaven, why do we need a resurrection? After all, would it not be better for us to all stay in heaven? And what are we going to be doing all day?

Good question. Jesus says, "Whoever eats my flesh and drinks my blood has eternal life" -John 6:54. And He makes it clear that this includes Abraham, Isaac and Jacob. (Matthew 22:32) "I say to you that many will come from the east and the west, and will take their places at the feast with Abraham, Isaac and Jacob in the kingdom of heaven." --Matthew 8:11 "By faith Abraham... But as it is, they desire a better country, that is, a heavenly one." --Hebrews 11:8-16

2 Corinthians 5:8 "Yes, we are of good courage, and we would rather be away from the body and at home with the Lord."

Acts 7:59 "Lord Jesus, receive my spirit!" -Stephen

Christians' desire is to be with the Lord, because we love Him so and desire Him more than anything. "Whom have I in heaven but you? I desire you more than anything on earth. I am my beloved’s and my beloved is mine. He is mine forever." Psalm 73:25; Song of Solomon 6:3; Psalm 73:26

"Set your minds on things above, not on earthly things. For many, of whom I have often told you and now tell you even with tears, walk as enemies of the cross of Christ... with minds set on earthly things." Colossians 3:2; Philippians 3:18-21

As we see Stephen says above, the Christian's Spirit goes to heaven. But this is not our final destination. For if we finish John 6:54 Jesus goes on to say of the Christian who HAS eternal life, "and I will raise him up at the last day." We see what happens on that last day in Revelation: "After these things I heard what was as a loud voice of a great crowd in heaven. And I saw a new heaven and a new earth; for the former heaven and the former earth had passed away, and the sea is no more. I saw also the holy city, New Jerusalem, coming down out of heaven from God and prepared as a bride adorned for her husband. With that I heard a loud voice from the throne say: “Look! The tent of God is with mankind, and he will reside with them, and they will be his peoples. And God himself will be with them. and thus we shall always be with [the] Lord." Revelation 19:1; 21:2-3; 1 Thessalonians 4:17