But according to my judgment, the most important point to be attended to is this: above all things, see to it that your souls are happy in the Lord! Other things may press upon you; the Lord's work even, may have urgent claims upon your attention. But I deliberately repeat, it is of supreme and paramount importance that you should seek above all other things to have your souls truly happy in God Himself. Day by day seek to make this the most important business of your life.
George Mueller, A Narrative of Some of the Lord's Dealings with George Mueller.