This parsha begins in what seems to be a regular way but with a twist. We are told that G-d appeared to Avraham, but we are not told the reason why - no prophecy, no command. Rashi says G-d appeared for the purpose of visiting the sick. The Ramban builds on this. The deeper meaning here is that G-d showed favor to Avraham, following Avraham’s performance of Brit Milah, by resting His presence upon him.
The Ramban cites examples where a person’s high spiritual achievement earns them a visit from G-d. This happened after the constructing of the Mishkan, and at the Yam Suf to the entire Jewish nation. This occurred to Yaakov in his dream about angels. It is a gift from G-d when He visits without a reason, just to be with us. We may learn from this that a great gift we can each give each other is to visit and be with one another without words conveyed.
There is a contrast in this parsha between those who fear G-d and those who don’t. Avraham tells Avimelech that there is no fear of G-d in his place and that without that a man could readily kill another. Later, the spot of the Akeida is marked as a place of fear of G-d. It is called The Place That G-d Will Show. There is a connection between the word for seeing and the word for fearing. When you see clearly, you come to fear G-d. Avraham who truly feared G-d asks G-d not to kill Sedom’s tzadikim along with the reshaim. Avimelech co-opts these words and uses them selfishly to save himself alone. Avimelech’s name means “my father was king. Avraham’s name means “kings will come from you.” These two men had a different vision and a different approach.
Lot, similarly misses the mark of fear of G-d. he tries to be like Avraham. But he chooses materialism over spirituality. He uses language similar to Avraham’s but in a warped way. They both address why the angels visited them, but Lot misses the mark.
(Adapted from the original thoughts of Rabbi Yitzchak Twerski)
After the Akeida G-d says, “Now I know that you fear G-d.” But wasn’t it clear that Avraham feared G-d before this? The point here (as the Netziv sees it) is that as much as Avraham feared G-d, his calling card was love of G-d. Given the command to kill their son most people would fall back on their closeness with G-d and ask for a reprieve. But Avraham proved that he was balanced that his love of G-d did not over ride his fear. Perhaps (as my student Ariel Sandor suggested) this explains why an angel speaks to Avraham at the end of this story and not G-d Himself. This stresses the idea of distance that must be balanced alongside closeness and love.