what Jesus meant by that is just that many rich people will value their money over Him and will find security in it instead of Him. It's not a cut-out law though. Abraham, Isaac, and Jacob were all rich and had very close relationships with God (though if you pay attention to details it appears Issac's relationship with God might not have been near as close as Abraham and Jacob's, but still was good). David was a king, and thus was rich. So Jesus isn't saying it's impossible; he's just saying that the poor are far more likely to look up for dependence rather than within.
