Sometimes The Outer Limits writers and producers get it right / correct! This is a wonderful episode with good character development, plot twists, possible evil doings, and at least two lessons.
The main lesson is one we should all know and check our lives and actions against. Fear of the unknown doesn't mean it is bad. Yes, it is wise to be careful but sometimes a person's action can - in the end - be full of love both for their own race and ours.
The second lesson is we must look forward for a fixation on (not learning from) the past can lead to your destruction.