For the Greeks, some emotions, such as love or fighting, were so powerful as to defy explanation. So they associated these emotions with deities, such as Aphrodite (Venus) or Ares (Mars). The priests of the Olympian gods did not take control of their worshippers and tell them what to do, but rather, expounded the main qualities of their deities. That helped the faithful to be reconciled with their human nature and their world.
Today, the Olympian gods have no followers, but we know enough about human physiology to explain the same emotions by the effect of hormonal and other systems that have developed over millions of years to help us adapt to our environment. Without love, we would not be here. If we were not willing to fight, we would be dispossessed. Without whatever hormone(s) – including vasopressin – create the herd instinct, life would be intolerably chaotic.
Here, then, are some Greek gods (or divinities) and hormones that contribute to the feelings that were formerly associated with them: