Thinking about Heaven, Part 2

I hope my last blog post got you thinking about the things that help you to "set your minds on things above, not on earthly things" (Colossians 3:2).  One of the reasons, according to the New Testament, that Christians are encouraged to look forward to Heaven is because that is the place of our true citizenship.  If that's the case, then Heaven should be a primary source of influence on our motivations, attitudes, decisions, and actions.  It is very clear when reading the New Testament that this was true about the apostles and early Christians.  But in our day and age we seem to have lost a clear, compelling, and inspiring vision of Heaven that motivates us.  Why is that?  What has clouded our vision of Heaven?  And exactly how should Heaven affect our lives in the here and now?