"Christianity produces a meaningful life."

I'm confused. I thought Christianity is about obtaining a get-out-of-hell-free card. Compared to eternity life on earth is literally nothing. Nothing that happens in this life is more important than avoiding spending eternity in hell. Pain and suffering in this life are nothing compared to pain and suffering in hell. Seeking joy or satisfaction in this life are fool's errands, if you end up in hell.

If avoiding hell in the next life is what this life is really all about, then why do so many Christians have earthly concerns? Why do they pay to send their children to college or strive to own a nice house and a nice car or buy life insurance or try to be successful as defined by the secular world?