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The word modest appears just once in the King James Authorised translation.
1Timothy 2:9 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;
The New Revised Standard version translates it thus:
NRSV 1 Timothy 2:9 also that the women should dress themselves modestly and decently in suitable clothing, not with their hair braided, or with gold, pearls, or expensive clothes,
In his first letter, Peter gives the following instruction to wives who have believed the gospel and been baptised into Christ:
1 Peter 3:3 Whose adorning let it not be that outward adorning of plaiting the hair, and of wearing of gold, or of putting on of apparel; 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.
NRSV 1 Peter 3:3 Do not adorn yourselves outwardly by braiding your hair, and by wearing gold ornaments or fine clothing; 4 rather, let your adornment be the inner self with the lasting beauty of a gentle and quiet spirit, which is very precious in God’s sight.
In his first letter to Timothy, Paul uses the same Greek word (kosmios) translated ‘modest’ in its other sense of ‘good behaviour’.
1 Timothy 3:2 A bishop then must be blameless, the husband of one wife, vigilant, sober, of good behaviour (kosmios), given to hospitality, apt to teach;
For those in Christ (both men and women), modesty in dress and behaviour are necessary to avoid bringing the name of Christ into disrepute.
Our lives are to be lived to give glory to God.
1 Corinthians 10:31 Whether therefore ye eat, or drink, or whatsoever ye do, do all to the glory of God.
Colossians 3:17 And whatsoever ye do in word or deed, do all in the name of the Lord Jesus, giving thanks to God and the Father by him.
Colossians 3:23 And whatsoever ye do, do it heartily, as to the Lord, and not unto men;
Our lives are to be lived in holiness:
1 Peter 1:15 But as he which hath called you is holy, so be ye holy in all manner of conversation (behaviour); 16 Because it is written, Be ye holy; for I am holy.
And in that which is above reproach:
Philippians 4:8 Finally, brethren, whatsoever things are true, whatsoever things are honest, whatsoever things are just, whatsoever things are pure, whatsoever things are lovely, whatsoever things are of good report; if there be any virtue, and if there be any praise, think on these things.
I hope this helps.