Answer
To put it bluntly, nightclubs are part of the world which is controlled by Satan. They are designed for the purpose of giving oneself over to sinful desires. Nightclubs exist primarily for two purposes: drinking alcohol and meeting members of the opposite sex, most often with sexual activity in mind. Yes, there are music and dancing, but primarily singles in particular go clubbing to drink and meet someone. Nightclubs are of the world, and, while Christians are to be in the world, we are not to be of it. Being of the world means to be interested in and desiring those things that appeal to the sinful nature.
Paul, speaking to Christians, addresses the issue of worldly practices in Ephesians 4:17-24, "So I tell you this, and insist on it in the Lord, that you must no longer live as the Gentiles do, in the futility of their thinking. They are darkened in their understanding and separated from the life of God because of the ignorance that is in them due to the hardening of their hearts. Having lost all sensitivity, they have given themselves over to sensuality so as to indulge in every kind of impurity, with a continual lust for more. You, however, did not come to know Christ that way. Surely you heard of him and were taught in him in accordance with the truth that is in Jesus. You were taught, with regard to your former way of life, to put off your old self, which is being corrupted by its deceitful desires; to be made new in the attitude of your minds; and to put on the new self, created to be like God in true righteousness and holiness." Here Paul describes those who exclude God and give themselves over to sensuality for the practice of every kind of impurity with greediness.
Obviously, God does not desire us to give ourselves over to sin so easily and willfully. Notice what God says here, "put off your old self, which is being corrupted by its deceitful desires." It’s interesting to note that God says when we give ourselves over to our sin nature, we are being deceived by our desires. Satan is a master counterfeiter. In other words, Satan presents something that appears on the surface to be attractive. The lure of clubbing is that it is very enjoyable, fun, and exciting. What we don’t see are the consequences because Satan keeps the sensual attraction at the forefront of our minds. Sex, alcohol, and drugs—all found in most nightclubs—are very destructive, both physically and spiritually. God has a place for sex where it is the most enjoyable—in monogamous marriage, where there are no STDs, HIV, guilt, aloneness—and those who don’t believe God in this are short-changing themselves.
God desires for us to be righteous and holy because He created us to be that way. The benefits of living the life that God intended far exceed the petty, short-lived thrills that this world offers. Many who are or used to be in the nightclub lifestyle say the same thing—there is no joy, there is no fulfillment; there is only emptiness. Only God can fulfill our needs and give us the joy and happiness we all seek. Clubbing offers nothing more than a very cheap imitation. There is no lasting joy to be found in nightclubs, only temptation to sin.
Such places are most especially not for Christians. Aside from the obvious temptations, there is the issue of our Christian witness in the world. When unbelievers see a professing Christian engaging in a sinful lifestyle, Christ is maligned and demeaned. We are to let our lights shine before men so they see our good works and glorify our Father who is in heaven (Matthew 5:16). It’s hard to see how the light of our new life in Christ can shine in a nightclub. Even if the Christian is not indulging in the sinful activities, the witness he or she presents to the watching world by just being there is destructive and must be avoided.