"And they did pray unto the Lord their God continually, insomuch that the Lord did bless them, according to his word, so that they did wax strong and prosper in the land."
Prayer is always a good idea. this scripture seems to be saying that it is all about consistency. If we pray consistently, then good things will naturally follow. I don't think that it is because we are following a commandment necessarily, although that is, of course, good... I think that what happens when you pray consistently and often is that you naturally develop a relationship with God, and that relationship affects all areas of your life, making you more confident, more aware of your personal power for good... more loving, basically more everything... more of what you should be. And when you are that, then how can you help but to wax strong and prosper? :)