1 Thessalonians 3:13

so that He may establish your hearts blameless in holiness before our God and Father at the coming of our Lord Jesus Christ with all His saints.

Surrounding context

3:12 And may the Lord make you increase and abound in love to one another and to all, just as we do to you,

3:13 so that He may establish your hearts blameless in holiness before our God and Father at the coming of our Lord Jesus Christ with all His saints.