“Be careful not to forget the covenant of the LORD your God…. For the LORD your God is a consuming fire, a jealous God” (4: 23 – 24). God reiterates this same self-characterization repeatedly in Scripture (Ex. 20: 5; 34: 14; Deut. 5: 9; 6: 15; Josh. 24: 19; Ezek. 39: 25; Joel 2: 18; Nah. 1: 2; Zech. 1: 14; 8: 2). God brooks no rivals. He is God and there is no other; therefore, He will not tolerate the worship of any would-be-gods. God is a consuming fire (4: 24) blazing against every vestige of idolatry. He shares His glory with no one.
God has an uncontestable right to be jealous. He created each of us. We owe our physical life to Him. He changed us. We owe our spiritual life to Him. What’s more we promised fidelity to Him and Him alone when we were saved. At conversion we turned to God from idols to serve the living and true God (1 Thess. 1: 9). That’s why Paul could say, I am jealous over you with a godly jealousy, because I have promised you in marriage to one husband – to present a pure virgin to Christ (2 Cor. 11: 2). The Apostle feared, however, that as the serpent deceived Eve by his cunning, your minds may be corrupted from the complete and pure devotion to Christ (2 Cor. 11: 3).
Anything less than complete and pure devotion to Christ prompts the jealousy of our God and rightfully so. Let’s say that a man marries a woman and at the altar he says to her, “Honey, I love you and I will be true to you 99.9% of the time but the other.1% of the time I will see other women.” Any woman who doesn’t lift her wedding gown and become a runaway bride at such words is an idiot. Marriage demands absolute fidelity and so does Christianity. God takes no pleasure in a divided heart regardless of what percentage belongs to Him. He has every right to all our heart and should expect nothing less.
Thankfully, in the same breath where God first informs us that He is a jealous God He also tells us that He shows faithful love to a thousand [generations] of those who love [Him] and keep [His] commands (Ex. 20: 5 – 6). If we have been unfaithful to Him His faithful love is ready to welcome us back to growing fellowship if we will only confess and repent of our sin.