Dvar Torah by Rabbi Abraham J. Twerski
The Torah relates that when the matriarch, Sarah, was told that she would bear a child at the age of 90, she laughed “inwardly,” thinking, “How can I bear a child at my old age?” God then said to Avraham, “Why did Sarah laugh? Is there anything that is beyond God?” Avraham reprimanded Sarah, but “Sarah denied, saying ‘I did not laugh’ for she was frightened.” Avraham then said to her, “No, you laughed indeed” (Gen. 18:12-14).
The Rabbi of Gur says that it is impossible to think that Sarah lied. The Midrash tells us that Sarah was totally free of sin (Bereishis Rabbah 58:1). He, therefore, interprets the verse as saying not that Sarah denied, but that Sarah was in denial.
Her disbelief that she could carry a child was “inward” — deep in the recesses of her subconscious. Sarah was not even aware of this thought. Only God Who knows a person’s innermost thoughts and feelings, was aware of it. When Avraham reprimanded her for this thought, Sarah could not even imagine that she could have harbored disbelief of God’s omnipotence. Her reverence of God was so great that a thought such as this was beyond her.
The verse thus reads, “Sarah was in denial because she was so God-fearing.” Sarah was certain that she was speaking the truth when she said, “I did not laugh.” Sarah did not deny or lie. She had no access to her subconscious.
If a person cannot be aware that he is in denial, how can we protect ourselves from being blind to reality? There is one way — by listening to teachers and sincere friends who are objective and can see that which we cannot see.