One of the Salaf, Imam Abu Al-Aliyah rahimahullah said, "I would travel for days to meet a man and the first thing I would notice about him is his prayer. If he would establish the prayer perfectly and on time, I would stay with him and hear the knowledge he had. If I found him to be careless concerning the prayer, I would leave him and say to myself that for things other than the prayer, he would be even more careless." (Hilyat Al-Awliya, 2/312)