One day we will all find out that being sincere, does not give us license to be wrong. Truth demands investigation and commitment. Our conclusions must be in keeping with truth that can be tested. To be handcuffed by a lie, is the worst of all imprisonments.
— Ravi Zacharias, from The Lotus and The Cross, Introduction
Sincerity has no power to create truth…. It has social-intellectual power, no question, but the issue is truth. If someone holds a belief sincerely, they will orient their life around it, and you have to be respectful of that person and that life, but you want to—in the name of Christ— challenge the belief if it goes against a biblical worldview.
— Douglas Groothuis, from Worldviews, Truth, and Knowledge Part 2 at 16:20