MacArthur on Integrity

Ethical integrity is one of the indispensable attributes of Christlike character. As vital as it is to be sound in doctrine and faithful in teaching the truth of Scripture, it is by no means less crucial for Christians to be upright in heart and consistent in our obedience to the moral and ethical principles of God’s law.

…It’s probably not overstating the case at all to say that the single most important battlefield in the struggle for integrity is your own mind. That’s where everything will actually be won or lost. And if you lose there, you have already ruined your character. A corrupt character inevitably spoils the reputation, too, because a bad tree can’t bring forth good fruit (Matt. 7:18).

…the person who neglects ethical integrity is telling a lie about God with his life and his attitude. If he calls himself a Christian and professes to be a child of God, he is in fact taking God’s name in vain at the most fundamental level.

Excerpts from Above Reproach at Ligonier Ministries