It's one of the biggest deceptions known to mankind - the attempt to achieve a higher level of personal improvement through our works and efforts. Adam and Eve were distracted by the glossy appearance of its fruit and the rest of the world followed suit. Israel demonstrated the futility of trying to establish their own righteousness through the works of the law by pursuing a level of improvement that would make them acceptable to God. It falls short every time and fortunately, it is something Jesus redeemed us from.