How Should the Outward and Inward Submission to Allah Be?

The Islam of a person is his submission to Allah the Exalted, outwardly and inwardly. As for the inward submission, the servant submits to his Rabb (Lord) by rectifying his creed and his heart. And that is by believing in everything mandatory to believe in, according to what came in the previous hadith of Jibril (i.e., pillars of Iman). As for outward submission, it is through rectification of the apparent actions, such as the statements of his tongue and the actions of his limbs. And people differ, outwardly and increasingly, in their Islam. Likewise, people differ in their forms and appearances. There are the tall and the short. The stout and the thinner. The ugly and the beautiful. They all differ in appearance. Likewise, they differ in their Islam (submission) to Allah, the Almighty, such that Allah, the Exalted said in His Book: {Not equal among you are those who spent and fought before the conquering (of Makkah, with those among you who did so later). Such are higher in degree than those who spent and fought afterwards. But to all Allah has promised the best (reward).} [Al-Hadid:10]