The Greeks either had a very good imagination or gods/ goddesses are real what do you think

The Greeks along with many other societies had a faded knowledge of the fallen angels who left heaven and came to earth and took for themselves human woman and had childeren with them.. these children called giants in the Bible where great warriors so over the generations stories about them ended up identifying them as gods like the Greek and Indian gods

So there is only One God but there are a lot of spirits who desire to be gods and worshipped as gods..

(Genesis 6:1-4) "And it came to pass, when men began to multiply on the face of the earth, and daughters were born unto them, {2} That the sons of God saw the daughters of men that they were fair; and they took them wives of all which they chose. {3} And the LORD said, My spirit shall not always strive with man, for that he also is flesh: yet his days shall be an hundred and twenty years. {4} There were giants in the earth in those days; and also after that, when the sons of God came in unto the daughters of men, and they bare children to them, the same became mighty men which were of old, men of renown."