Make every effort to live in peace with everyone and to be holy; without holiness no one will see the Lord.

Two other key verses come to mind:

Make every effort to keep the unity of the Spirit through the bond of peace. (Ephesians 4:3)

 If it is possible, as far as it depends on you, live at peace with everyone. (Romans 12:18).

I find it interesting that the writer seems to be bracket peace and holiness together. To my mind, living at peace with others is a social manifestation of holiness. As we grow in our vertical relationship with God, so there should be a healthy outgrowth into our relationships at a horizontal level. (See 13:1-3, 7, 16,17).

What will it mean to ”Make every effort to live in peace with everyone and to be holy…”? Each one of us will need to think and pray this through, and then act accordingly.

‘It is not possible to live at peace with everyone, because some people will oppose us simply because of our faith in Christ. But we must try as far as possible to remain at peace with everyone. And if we are supposed to remain at peace with non-believers, how much more should we strive to remain at peace with our fellow-believers.’ Tom Hale: ‘Applied New Testament Commentary’, p.880.

Clearly, ”holiness” is not an optional extra for a few especially saintly types. Literally, ”be holy” means ‘pursue holiness.’ But we know from verse 10 that we cannot grow in holiness apart from God’s work in us.

The implications of verse 14 will be drawn out in the following verses