First off, there is no dress code in the Bible when it comes to requiring certain types of clothing for church services. Although the Bible does not have a "church dress code", here are some points to consider.
- God expects men and women to dress "modestly", but beyond that, it is up to the individual.
- It is common to see Christians in the USA "dress-up" somewhat when coming to church services. This varies between different locations and cultures.
- Those who choose to dress more formal usually feel it is more "respectful" to the occasion. This decision, however, is very much a personal choice and not a "requirement" in the Bible.
- Christians are commanded to "not give preference" to a rich person in fine clothes at church verses a poor man in dirty clothes. (Note the following passage).
- My brethren, do not hold your faith in our glorious Lord Jesus Christ with an attitude of personal favoritism. For if a man comes into your assembly with a gold ring and dressed in fine clothes, and there also comes in a poor man in dirty clothes, and you pay special attention to the one who is wearing the fine clothes, and say, "You sit here in a good place," and you say to the poor man, "You stand over there, or sit down by my footstool," have you not made distinctions among yourselves, and become judges with evil motives? (James 2:1-4 NASB).