Say Less. Mean More.
You don't owe anyone a closing argument justifying your convictions.
The Lord Jesus Christ said, "Let your communication be, Yea, yea; Nay, nay" (Matthew 5:37). Jesus wasn't being cold. He was showing you what character looks like.
A man of God whose word means something doesn't need to defend it. Say what you mean. Mean what you say. Move on.