How can one fortify oneself against trials (fitna) in their religion, and what should one do to repel these trials if they fall into them?

The righteousness of one's religion is the Muslim's happiness and triumph in the Hereafter. To fortify one's religion against trials (fitan), the following can be done: staying away from environments of religious and moral corruption, strengthening faith by performing acts of obedience and abandoning forbidden acts, frequently supplicating (du'a), keeping away from bad company, and learning religious knowledge and consulting trustworthy scholars. For one who has fallen into a trial, they must hasten to sincere repentance, change their environment, supplicate, perform good deeds, and identify the cause of the trial and its remedy.