The Bible states, “If a woman have long hair, it is a glory given to her for a covering” (I Cor. 11:15) If God calls hair a GLORY, you really should care what He means. Christians should be known for their moderation (Phil. 4:5). This includes hair and grooming.
While tasteful, attractive styling should be sought, you should never do so out of vanity. Notice I Timothy 2:9-10: “In like manner also, that women adorn themselves in modest apparel, with shamefacedness and sobriety; not with braided hair, or gold, or pearls, or costly array. But (which becomes women professing godliness) with good works.”
The term “braided hair, or gold or pearls” refers to a hairstyle popular in Paul’s day. It was not speaking of simply braiding your hair. Women, in that time, would often immodestly braid their hair, weaving expensive jewelry into it.
You may also want to notice that I Corinthians 11:15 states, “long hair.” This does not mean you should never cut your hair. Nowhere in the Bible does it forbid modest cutting, curling or styling in a feminine manner. Any style and many lengths of hair are appropriate if its length can be considered a “covering.”
Also notice: “…let [adorning] not be that outward adorning of plaiting the hair, and of wearing of gold, or of putting on of apparel” (I Pet. 3:3). Verse 4 goes on to show that it is what we look like on the inside (our attitude) that is important to God.