Blessings Received from Heresies

I surely do not have time to study all these things, and it would be damaging to my experience to delve into false theories, so how can they be a blessing to me? How can I distinguish between what is truth and what is error? How does God use these heresies?

The Spelling of Love. Rebuke or Discipline or The Greatest Blessing

These are just a few examples of the courteous rebuke in Scripture. We could add Nicodemus, David, Cain, Saul—the first king of Israel, Saul who turned to Paul, and the list goes on. Somehow, I think we have a real problem or difficulty accepting the reality of this side of Christ. But as Inspiration says, there was a wise purpose in everything Christ said and did. So, what was His purpose?