What does it mean that God is a jealous God?

When scripture describes God as a jealous God, it signifies His intense desire for fidelity and devotion from His people. This jealousy is akin to that of a loving spouse who desires genuine love and commitment. In the context of the sermon, it highlights that God will not share His glory with anyone or anything else. This serves as a warning against idolatry and a call to maintain our first love for God above all else. The jealousy of God not only underscores His holiness but also reveals His infinite love and commitment to His people, desiring their undivided hearts.