Wamina annasi man yaAAbudu Allaha AAala harfin fa-in asabahu khayrun itmaanna bihi (surah Hajj: 11)

Tafseer Tafheem-ul-Quran by Syed Abu-al-A'la Maududi

(22:11) And there is a type of man who serves Allah standing on the borders (of the Faith *15 ); is if some good comes to him, he is satisfied (with his Faith), but if he encounters a trial, he turns his back (upon it). *16 Thus he loses both this world and the Hereafter: this is the manifest loss. *17

Wa minan naasi mai ya`budul laaha `alaa harfin fa in asaabahoo khairunit maanna bihee wa in asaabat hu fitnatunin qalaba `alaa wajhihee khasirad dunyaa wal aakhirah; zaalika huwal khusraanul mubeen

*15) This type of man is a time server, who stands on the boundary line between Islam and kufr so that he may join the winning side whether it be Islam or kufr.
*16) As this type of man has a weak character and wavers between kufr and Islam he becomes the slave of his "self". He accepts Islam for the sake of selfinterest: he is faithful to it if all his wishes are fulfilled and he has a life of ease and comfort; he is well-pleased with his Allah and is "firm" in his faith. On the contrary, if his "faith" demands some sacrifice from him, or he is visited by some affliction, or encounters some hardship and loss in the way of Allah, or he does not have his way, he begins to waver about the Godhead of Allah and the Prophethood of the Messenger and becomes sceptical about everything of the "Faith". Then he is ready to bow down before any power from which he expects some benefit and security from loss.
*17) This is a great moral proposition that has been stated concisely. The fact is that the wavering man remains a loser in this world as well as in the Next World, and fares worse even than an unbeliever. The unbeliever applies himself exclusively to the benefits of this world and becomes more or less successful in his object because he is not handicapped by the fear of Allah, accountability of the Hereafter and restrictions of Divine Law. Likewise a true believer follows the way of Allah with fortitude and perseverance and may as well become successful in this world, but even if he loses it altogether, he is assured of success in the Next Y World. But the "wavering Muslim" becomes a loser both in this world and in the Next World because he is handicapped by doubt and indecision and cannot make his choice between the two worlds. As he cannot decide whether there is Allah and the Hereafter, he cannot apply himself exclusively to the worldly affairs with that single-mindedness which the unbeliever enjoys. And when he thinks of Allah and the Hereafter, the allurements of this world and the fear of the disadvantages here and the abhorrence of observing the Divine restrictions do not let him apply himself exclusively to the demands of the Hereafter. This conflict between "Godworship" and "World-worship" makes him a loser in this world as well as in the next.