Romans 3:4

Certainly not! Indeed, let God be true but every man a liar. As it is written: "That You may be justified in Your words, And may overcome when You are judged."

Surrounding context

3:3 For what if some did not believe? Will their unbelief make the faithfulness of God without effect?

3:4 Certainly not! Indeed, let God be true but every man a liar. As it is written: "That You may be justified in Your words, And may overcome when You are judged."

3:5 But if our unrighteousness demonstrates the righteousness of God, what shall we say? Is God unjust who inflicts wrath? (I speak as a man.)

Translation and sources