William Burkitt on 1 Peter 5:12

Observe here, That our apostle, to encourage these suffering Christians to a resolved perseverance in the Christian religion, assures them that it was undoubtedly from God, the unquestionable truth of God, and therefore neither seducers on the one hand, nor persecutors on the other, should be able to shake them, or cause them to fall from their own steadfastness; a firm belief of the certainty and excellency of Christianty conduces much to the establishment of those that have newly embraced it; if we be once assured that it is the true grace of God wherein we stand, it will cause us to stand steadfast.