Joshua 24:19

Then Joshua said to the people, “You will not be able to serve the Lord (if you serve any other gods), for He is a holy God; He is a jealous God (demanding what is rightfully and uniquely His). He will not forgive your transgression (of His law) or your sins.

A god can be anything in our lives that takes center stage of our love, time, and devotion over our focus on God. We can be overly focused on our family, children, work, money, and possessions. We cheat ourselves out of a relationship with God and His blessings in our lives. Our fulfillment in life comes only from God, and nothing on earth will ever satisfy.