We are truly saddened to hear about the struggles of your son, but we are here to intercede and pray with you. Firstly, it is so important to remember that it is by the name of Jesus Christ that we have access to the Father.
First let us address the drinking and gambling. These are both strongholds that can be bound and broken only by the blood of Jesus.
1 Corinthians 10:13 WEB "No temptation has taken you except what is common to man. God is faithful, who will not allow you to be tempted above what you are able, but will with the temptation also make the way of escape, that you may be able to endure it."
Also it does sound like your son is pressuring himself and that is when he is drinking. We should pray that your son looks to God for help for all things. 1 Peter 5:7 WEB says "casting all your worries on him, because he cares for you."
Finally, we need to address your son being an unbeliever. Let us pray firstly that your son comes to a saving knowledge of Jesus Christ. There is no other name by which we can be saved. Acts 4:12 WEB says "There is salvation in none other, for neither is there any other name under heaven, that is given among men, by which we must be saved!"
Let us pray.
Dear Heavenly Father,
We come before You today, lifting up this beloved son to You. Lord, we pray that You break the chains of gambling and drinking that have held him captive. Give him the strength and wisdom to resist these temptations and provide him with a way of escape.
We also pray, Father, that You help him to cast all his worries on You, knowing that You care for him deeply. Help him to understand that he can trust in You for all things.
Most importantly, Lord, we pray that You reveal Yourself to him in a powerful way. Open his heart to receive the good news of Jesus Christ, and draw him to a saving knowledge of You. We pray as the scriptures say, you do not want anyone to perish but everyone to come to repentance.
We ask to break any generational curses on this family and that this family can have a new beginning in Jesus Christ.
In Jesus' mighty name, we pray. Amen.
You are not alone in how you are dealing with this situation. Keep praying and trusting God for your son. Continue to have faith for his salvation and healing from these temptations and struggles.