This scripture, in context, is referring to the conduct of Christian women.  At first glance one might interpret that for women to be acceptable to God, they should always be extremely plain, very simply dressed, and unadorned with neither jewelry nor elaborate hairdos in order to be acceptable to God.  However, the next verse is a continuation of the thought begun in verse 3.

1 Peter 3:4:  “…But let it be the hidden man of the heart, in that which is not corruptible, even the ornament of a meek and quiet spirit, which is in the sight of God of great price.”

Women, or any follower of Christ, should not (merely or only) adorn themselves on the outside because the outside is corruptible, and will be tarnished with time.  But Christians should work instead on their heart attitude, their devotion to God, and their spiritual development which is truly beautiful in the sight of God. Please note, it is unnecessary to take this idea to the extreme and dress without care, without recognizing the proper attire for one’s environment. Jesus, himself, wore a coat without seams (John 19:23) – this was an expensive garment in Bible times.

On the other hand, it would be inappropriate for Christians to dress and act with an excess of extravagance. This would lead to the growth of pride for we know that the love of display and appearing well on the outside is a particular temptation to all. This would be the opposite of the cultivation of a spirit of meekness and humility, which the second verse advocates as what the Lord is looking for in the development of our characters.  Colossians 3:12: “Put on therefore, as the elect of God, holy and beloved, bowels of mercies, kindness, humbleness of mind, meekness, longsuffering…”

In addition, the majority of people look enviously on those who flaunt gratuitous displays of wealth and luxury.  The spirit of love should consider the sentiments of those they come in contact with and would not want to provoke anyone to envy, jealousy, or bitterness. James 2:5 tells us, “Nevertheless, you are doing the right thing if you obey the royal Law (God’s supreme law of Love) in keeping with the Scripture, ‘You must love your neighbor as yourself.’ 

With all this in mind, it would be best for all followers of Christ to dress and act in ways that are in moderation. Philippians 4:5: “Let your moderation be known unto all men.  The Lord is at hand.”  We want to be a good examples and good ambassadors to the world around us.

Additional Resource:
Christian Questions Podcast Episode #1240: Is It a Sin if I …? (Part I)
Examining whether how we dress and if gambling are sins
Preview Video
CQ Rewind Show Notes