Those who think they know something do not yet know as they ought to know. (NIV)
If anyone imagines that he has come to know and understand much [of divine things, without love], he does not yet perceive and recognize and understand as strongly and clearly, nor has he become as intimately acquainted with anything as he ought or as is necessary. (AMP)
And if any man think that he knoweth any thing, he knoweth nothing yet as he ought to know. (KJV)