Think it not strange; be not offended or troubled at persecution, as at a thing unusual or never heard of; it implies that they should reckon upon it beforehand, that they might not be surprised with it when it comes. The same word is used, 1 Peter 4:4. Concerning the fiery trial; the heat or burning, whereby he means great afflictions, especially those that are for rightesusness sake, as appears, 1 Peter 4:14, which are often compared to fire, as being alike painful and grievous to them as fire is to men's bodies; and because men are tried by them as metals are by fire, Psalms 66:10 Isaiah 48:10. Which is to try you: this he adds as the reason why they should not think strange of persecutions, viz. because they were sent by God, not for their destruction, but for the trial and exercise of their graces.
Related Commentaries of 1 Peter 4:12
1 Peter 4:12
12 Beloved, think it not strange concerning the fiery trial which is to try you, as though some strange thing happened unto you: