When you have a bad suspicion about a Muslim in your heart, you should increase your consideration toward him and make dua for him. This way you will infuriate Satan and will be able to drive him away. Because of this, Satan will be reluctant to put evil thoughts into your heart, afraid that you would increase your consideration towards your brother and will make dua for him again.
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-GhazaliYou must convince your heart that whatever Allah has decreed is most appropriate and most beneficial for you.
Al-GhazaliThis visible world is a trace of that invisible one and the former follows the latter like a shadow.
Al-Ghazali