‘And fitnah is worse than killing’ (Qur’an, 2:191)
WE learn from this ayah that al-fitnah — i.e. preventing the people from following their deen (Islam) — is a greater (crime) than killing them; because in their killing, the maximum they will miss out on is this worldly life. But if they are prevented from (learning and having) Emaan, then they will lose in this world and the Hereafter.
Many people approach the places of fitnah (e.g. a bad company or an environment that would corrupt their religious beliefs and morals) thinking this fitnah will not affect (or harm) them. But if they continue doing so, it won’t be long before they are overtaken by the fitnah. This is why the Prophet ﷺ said, “Let him who hears of the Dajjaal (Antichrist) go far from him for I swear by Allah that a man will come to him thinking that he (the Dajjaal) is a believer, then he will follow him because of the deceptive arguments he (the Dajjaal) will put forward (to confuse him).” (Sunan Abu Dawood, 4319; graded Saheeh by Shaikh al-Albani)
The important thing is that a person should not expose himself to fitnah. How many people approached the places of fitan thinking they were immune, but they were not!
[Source: Tafseer of Surah al-Baqarah by Shaikh Ibn al-`Uthaymeen (3/59-60); translated by Abu Sahl Fahad Barmem, ilm4all]