Non-Christians say some things like this, but Christians actually mean it. It must seem strange to unbelievers, who have yet to experience the joys, peace, and comforts that a relationship with Christ brings to our hearts, when we speak of longing to be with Christ in heaven. It must seem strange, but it shouldn't. We Christians are a group who long to be with Christ, who look forward to eternity in heaven and living forever. We are those who will take suffering now, often with a smile, because we know that there is more to life that simply living for today.
Christians set their affections on the things that are above.
This influences everything we do. Heaven is a place that is pure, majestic, and holy. It is the joy of the Christian that fellowship with God has been restored in Christ and that heaven is where we shall dwell with Him. In John Bunyan's book, Pilgrims Progress , he writes of the pilgrims drawing near to the gate of the Celestial City. A great many people came out to meet the pilgrims and the king's trumpeters saluted them with 10,000 welcomes.