Peter had told his readers in 1 Peter 2:18 that household slaves were to submit to their masters, whether they were good and gentle or were crooked. Crooked masters were likely to make things hard for their (defenceless) slaves and so in 1 Peter 2:19 Peter underscored the place of a godly conscience in the face of unjust suffering, describing such conscience as a gift from God. With the connective “for” in 1 Peter 2:20 the apostle now makes clear that he wants to draw out further the shape of this gift from God.
20 For what credit is it if, when you sin and are beaten for it, you endure? But if when you do good and suffer for it you endure, this is a gracious thing in the sight of God.