If you are looking for an exact dress code; like lengths of clothing and what parts of your body must be covered, you will not find such things in the Bible. However, if you are looking for Biblical principles that can guide you as a Christian in how to dress, the Bible does give these principles.

The Bible has clear guides on how to select your clothing;
1. Particularly at the point of PURCHASE, OR
2. WHEN YOU ARE CHOOSING WHEN TO WEAR IT.

Why are we considering this thought?
Because “Foolish people don't care if they sin, but good people want to be forgiven” Pro 14:9. This means good people want to know “Where do you draw the line?”. “Is lust the only consideration or criteria for judging what we should wear?” Some say after all “If someone is going to lust, they will lust no matter what I wear...”

“In like manner also, that women adorn themselves in modest apparel, with shamefacedness and sobriety; not with broided hair, or gold, or pearls, or costly array” I Timothy 2:9 KJV

This passage is probably the most popular in all Scriptures that is being taught by Christian teachers regarding Christian modesty.

Modesty in the way we dress is not just for church; it is to be the standard for all Christians at all times. In other words, the key to understanding what constitutes modesty in dress is to examine the attitudes and intents of the heart both at the point of purchase of the dress and when it is being worn. Those whose hearts are inclined toward God will make every effort to dress modestly, decently, and appropriately.

In summary, dressing modestly biblically-speaking means to dress appropriately for the occasion. If you as a Christian wear the wrong clothing for the wrong occasion, it might offend others and also bring shame on Christ if they know you are a Christian. A bikini is meant for the beach/pool, but if you wore it to Church others would be offended, and they would be right in being offended, because that is inappropriate attire for Church.

All Paul is saying in the scripture 1 Tim 2:9 is; it is appropriate and proper for a woman to be fully clothed and covered for Church gatherings. While Paul’s statement is confined to the Church assembly, this doesn’t mean that the principle of modesty cannot apply elsewhere, especially when we understand that modesty means CHRISTIANS OUGHT TO WEAR CLOTHING THAT IS APPROPRIATE TO THE OCCASION.

Modest – This means “seemly” or “appropriate”. Paul is telling women to wear clothing that is appropriate for the given situation.
Shamefacedness – This means to show honor, respect or reverence to others when you appear.
Sobriety – Paul was saying a woman needed to dress for Church services in a way that showed self-control.

Note that, Paul is not saying it is wrong for a Christian woman to have nice hair, jewelry or dresses. What he is saying is; the Church assembly should not be turned into a fashion show (Unfortunately in many of our modern Churches today that is just the case). Paul is not saying women cannot wear nice Sunday dresses, he is just saying women should not go overboard or be trying to compete with one another in what they wear for worship.

In the end, whatever, we do as men or women, or whatever we wear should all be done in a manner that would bring glory to God, and not bring shame to Him in the eyes of the world.