Assuming your spouse realizes the detrimental results of pornography use to his/her own spiritual well-being and the harm it does in his/her relationships, your responsibility is to stay in faith for your spouse.
Pornography is one of Satan’s tactics to trap men and women and fulfill his ultimate intent to kill, steal and destroy lives (John 10:10).
So what do you do? Pray God’s Word over your spouse. First John 5:4-5 says, “For whatever is born of God overcomes the world. And this is the victory that has overcome the world—our faith. Who is he who overcomes the world, but he who believes that Jesus is the Son of God?” God wants your spouse to walk free from those things that would be a hindrance to life, and Jesus has made it possible to do so!
So, pray for your spouse like this:
“Father, ________ (spouse’s name) has sinned against You and right now I intercede on his/her behalf, declaring he/she will choose to turn away from that sin and leave it behind. I thank You for Your forgiveness for this sin, and by faith I stand for his/her cleansing from all sin by the blood of Jesus. I confess over him/her Your empowerment to live a holy life right now, in Jesus’ Name. Amen!”
And a key to your answered prayer, according to Mark 11:22-25, is that when you stand praying, you forgive. So your stand of faith includes forgiving your spouse for this sin against you and your relationship.
Now, let God work in your spouse’s life. Your job is to daily thank Him for deliverance according to the Word you have prayed and believed!
Source: Kenneth Copeland Ministries