There are two kinds of Riya - Showing off-Ostentation ie pure ostentation and adulterated ostention. In pure ostentation "Riya" a man does a good deed only for worldly benefit. In Adulterated ostentation, a man does a good deed with the intention of reaping the benefits of the world as well as of the Hereafter.
Al-GhazaliDeclare your jihad on thirteen enemies you cannot see - Egoism, Arrogance, Conceit, Selfishness, Greed, Lust, Intolerance, Anger, Lying, Cheating, Gossiping and Slandering. If you can master and destroy them, then will be ready to fight the enemy you can see.
Al-GhazaliRemember it is the heart and not the body, which strives to draw near to God. By heart I do not mean the flesh perceived by the senses, but that secret thing which is sometimes expressed by spirit, and sometimes by soul.
Al-GhazaliIn the intricate paths of life when difficulties and hardships confront a man, and the darkness of difficulty and suffering becomes long, it is patience only that acts like a light for a Muslim, that keeps him safe from wandering here and there, and saves him from the muddy marsh of disappointment, desperation and frustration.
Al-GhazaliIf the first inward thought is not warded off, it will generate a desire, then the desire will generate a wish, and the wish will generate an intention, and the intention will generate the action, and the action will result in ruin and divine wrath. So evil must be cut off at its root, which is when it is simply a thought that crosses the mind, from which all the other things follow on.
Al-GhazaliWhatever the situation may be, in the recollection of death there is reward and merit. For even the man engrossed in the world benefits from it by acquiring an aversion to this world, since it spoils his contentment and the fullness of his pleasure; and everything which spoils for man his pleasures and his appetites is one of the means of deliverance.
Al-Ghazali