In the second commandment recorded in Exodus 20:4-6, we are given the second principle for a strong marriage,
"You shall not make for yourself a carved image—any likeness of anything that is in heaven above, or that is in the earth beneath, or that is in the water under the earth; you shall not bow down to them nor serve them. For I, the LORD your God, am a jealous God, visiting the iniquity of the fathers upon the children to the third and fourth generations of those who hate Me, but showing mercy to thousands, to those who love Me and keep My commandments."
God commanded that there be no carved images, whether in heaven, in earth, or in the sea. He wanted to make sure everything was covered. And He said not to bow down to them and worship them. God said, "Do not make images of Me and then worship them. Don not love or worship a substitute for Me. Love Me."
Religion has made pictures, statues, and idols and then called them holy. They are all imitations. They are all substitutes. And in marriage we should have no substitutes either.
Love your husband only. Love your wife only. Do not look for fulfillment in some other relationship or in some other thing. Find your fulfillment in that relationship.
Pornography is a substitute. When a man watches pornography, he is loving a substitute. He is directing his passion and his sexuality toward those images. That is a substitute, and he is robbing his wife of that intimacy.
Do not allow any substitute, no matter what it might be, to take the place of intimacy with your spouse.