Lest they should be converted, and I should heal them" signifies lest they should acknowledge truths and then depart from them and thus become profane.
He hath blinded their eyes and hardened their heart, that they should not see with their eyes, nor understand with their heart and be converted: and I should heal them.
The above list will hopefully provide you with a few useful examples demonstrating the appropriate usage of "should heal" in a variety of sentences. We hope that you will now be able to make sentences using this group of words.