Physical adultery is always the result of spiritual adultery. If we want to be faithful to our spouse, we must first be faithful to our God.
Joshua gathers all of the elders of Israel together to renew the covenant with them before God (Josh. 24:1). Joshua reviews Israel’s history, particularly focusing on the fact that their ancestors originally worshipped other gods (Josh. 24:2), and yet Yahweh God has been the one who has repeatedly saved, rescued, and blessed (Josh. 24:3-10). God has brought them into the land of promise and drove out the nations before them, not with their sword or bow (Josh. 24:11-12). God has lavished blessings upon His people and calls them to fidelity to Him, putting away the gods their fathers served (Josh. 24:13-15). The people respond by saying that they will serve the Lord since He has done all these things (Josh. 24:16-18). But Joshua is not satisfied, and pushes back, telling them that God is holy and jealous, and He will not forgive them if they forsake Him and turn away to other gods (Josh. 24:19-20). But when the people insist, Joshua instructs them to put away the foreign gods and incline their hearts to the Lord (Josh. 24:21-24). So Joshua makes a covenant with the people on that day, writing down the words of the covenant in the book of the Law, and set up a stone as witness of the covenant (Josh. 24:25-28).
Who is Your God?
The beginning of Joshua’s conquest rested entirely on this question. If Yahweh God is with Joshua and Israel, no man will stand against them (Josh. 1:5). God insists that Joshua must have courage and be strong but this is based squarely on the promise of God to be with him (Josh. 1:6-9). At the close of Joshua’s life, he gives this same exhortation to the elders of Israel. The conquest is not yet finished, therefore Israel must be very courageous, hold fast to the Lord their God, and love the Lord their God (Josh. 23:6-11). If they hold fast to God, one man will chase a thousand (Josh. 24:9-10), but if they turn to other gods, the anger of the Lord will burn against them and they will be destroyed from the land (Josh. 23:16). While the gods are different in some respects, the same principles apply to the New Covenant. James calls spiritual adultery “friendship with the world” (Js. 4:4) and it is marked by cursing (Js. 3:9), bitter envy, self-seeking (Js. 3:14-16), fights, lust, coveting, selfish pleasure, and pride (Js. 4:1-3). Jesus teaches that one of the fundamental divides in the world is between God and mammon/money (Lk. 16:13), and it’s no accident that Luke notes that the Pharisees were lovers of money just before Jesus reviews adultery (Lk. 16:18).
Failure of Loyalty
A significant failure of loyalty in a marriage doesn’t happen in one day. It begins with countless little acts of unfaithfulness: failure to call, failure to hug, failure to spend meaningful time together, etc. But if your job or friends or hobbies are stealing from your wife what is rightfully hers, then they are idols. Every wife, and certainly every Christian wife, has a god-given jealousy for her husband’s time and energy and affection. And your standard is your wife. You can also tell your idols by how much time you spend rationalizing and justifying. God is not disloyal to us. God is not distracted by other things. God is not too busy for His people. In fact, the gospel insists that His loyalty is fierce and breaks through centuries of coldness and hardness.
Failure of Leadership
Related to the previous point, sometimes husbands fail to lead. This consists of careful conversations with your wife where you plan your days, weeks, months, years together, where you listen to her concerns and make adjustments for her needs and desires. It may not be that your work or hobby is your god intentionally, but if you do not take time to listen to your wife’s opinion, then you are serving an idol somewhere. Jesus has not left us alone and without marching orders. He has given us His Spirit and His word, and the Spirit teaches us to pray. Jesus has come to open up communication between us and the Father. He has come to glorify the church so that she can carry on His mission in the world. Husbands, are you talking and praying with your wives so that they know the mission of your family?
As For Me and My House
There are meathead husbands who think that being the head of their family means being a calloused jerk, but they will be judged (1 Pet. 3:7). It is actually the opposite of tyranny for a man to worship the Triune God and to stand up and claim his complete and utter allegiance to this true God on behalf of his family (Josh. 24:15). That is courage and fidelity.