1 Peter 2 :9 Says:
But ye are chosen generation,a royal priesthood,an holy nation,a peculiar people; that ye should shew forth the praises of him who hath called you out of darkness into his marvellous light.
Priests offer sacrifices, so we're to proclaim the excellency of God who called us.
Revelation 1:6
And hath made us kings and priests unto God and his Father; to him be glory and dominion for ever and ever. Amen.
Hebrews 5:4
And no man taketh this honour unto himself, but he that is called of God, as was Aaron.
To proclaim the honour of God we must be called by God.
1 Peter 2:4-5
To whom coming,as unto a living stone, disallowed indeed of men,but chosen of God, and precious,
Ye also,as lively stones, are built up a spiritual house,an holy priesthood,to offer up spiritual sacrifices, acceptable to God by Jesus Christ.
1 Corinthians 1:9
God is faithful,by whom ye are called unto the fellowship of his son Jesus Christ our lord.
So we have obligation as people chosen by God to show forth the excellency of God.
Thanks be to God!