Agamemnon isn't the only guy who was asked by a god to sacrifice his child. Abraham, who is a major figure in Judaism, Islam and Christianity, was asked by his God to sacrifice his beloved son, Isaac.
When God told him to give Isaac as a burnt offering, Abraham set out to do as he was told. Right before he did it, however, an Angel swooped down and was like, "JK! God was just testing you."
Abraham then saw a ram caught in some briars and sacrificed it instead. This story reminds us a whole lot of the version of Agamemnon's story where Artemis swoops down at the last minute and gives Agamemnon a deer to sacrifice instead of Iphigenia.