Why do most Christians live like atheists?

Why do I know so many Christians who own vacation homes? Did not Jesus preach to sell everything and donate the proceeds to the poor? And why, if the next world is so heavenly and superior to this one, are Christians as determined to postpone death as atheists? Why do Christians go to the doctor -- if Jesus answers prayers, as the Bible claims very conspicuously, why should such people ever require human medical attention at all? And how can a group of people who claim to believe in a Messiah's message of "loving your enemies" be such relentless warmongers? All of this reminds me of a quote from Mark Twain: "If Jesus came back today, one thing that He would not be is a Christian."