God asked the wicked what right they had to declare His statutes, since they hated His instruction (Psalm 50:16, 17).
He also revealed to them that their behavior disqualified them, “When you saw a thief, you consented with him, and have been a partaker with adulterers. You give your mouth to evil, and your tongue frames deceit. You sit and speak against your brother; you slander your own mother’s son” (Psalm 50:18-20).
While we all sin, we cannot live in sin and tell others what God says about life. We qualify ourselves to speak the word of God by making sin the exception in our lives and not the rule.