Jesus said, "I say to you that everyone who looks at a woman with lustful intent has already committed adultery with her in his heart" (Matthew 5:28). Yes, watching strippers is a sin.
Is it a sin for Christians to watch strippers or go to a strip club?
We are often faced with satisfying the desires of what Romans 8 calls the flesh—our selfish wants—or living according to God's ways. We are given a choice, and, through the power of Christ, we can choose the things of the Spirit, the things of God. "For to set the mind on the flesh is death, but to set the mind on the Spirit is life and peace" (Romans 8:6).
Sex is a gift from God that He intends to have us enjoy within marriage (Hebrews 13:4; 1 Corinthians 6:18). When we attempt to satisfy our sexual desires outside of marriage, that is sin. Strip clubs offer sexual enjoyment outside of marriage, which is sin (1 Corinthians 6:9; Genesis 2:24; Matthew 19:6). The reason strip clubs exist is to promote lust, sensuality, perversion, and sexual immorality. The environment there is not welcoming to Jesus, and His followers should not go to such a place. Some, very few, Christians are called to minister to strippers and those entrapped in that industry. This is the only reason a Christian would enter a strip club that could remotely be in accordance with God's wishes.
However, the question raises a much more important issue—that of the consequences and remedy of sin. The Bible tells us that each person has missed the intention God has for us by sinning (Genesis 3:11; Romans 3:23; 5:12) and the punishment for sin is death (Romans 6:23). When questions arise about if this activity is sin, or that activity is sin, what we are sometimes trying to find out about is what does God want us to do or not do? We often want a defined set of rules to live by, thinking that if we can keep the rules well enough we'll earn God's favor. And, though God establishes His expectations about our behavior, our relationship with Him does not depend upon our adherence to rules.
Our relationship with God rests on our trust in what Jesus did on the cross—died for our sins to make us right with God (1 John 1:7; Titus 3:5). It is by God's grace that we are saved (Ephesians 2:8–10). We are also made new (2 Corinthians 5:17, 21; Colossians 1:10) and our desires begin to bend toward wanting to please God. Our aim shifts from wondering about offending God or trying to earn His favor by avoiding certain sins, to wanting to live a life that pleases Him. We come to desire to live a pure, righteous, even holy life (Matthew 5:8; 1 Peter 1:15–16). Rather than simply avoid that which is bad, we seek after that which is good. As Christians, we are accepted by God and that acceptance births in us a desire to honor Him (1 John 3:1, 9–10; Philippians 2:15).
So, when we ask if it is a sin to go to a strip club or watch strippers, the answer is yes. But instead of looking for a list of sins, as Christians, our primary focus should begin to shift to activities that please God (Philippians 4:8).
Is pornography a sin?
Does the Bible say anything about voyeurism?
Is masturbation a sin according to the Bible?
Is it a sin to have intrusive thoughts?
How can I have victory in overcoming sin?
Truth about Sin