If you have the Lord Jesus Christ, then you will have His grace. If you have God, then you will have His love and His peace. If you have the Holy Spirit, then you will have His fellowship. But, if you don’t, then you won’t.
Verse 14 is not a hopeful wish for love and peace for everyone. Verse 14 is a promise to only those who have the Lord Jesus Christ, God, and the Holy Spirit.
We get a clue about this fact in Verse 11: “… and the God of love and peace will be with you.” Verse 11 infers that the God of love and peace is not with everyone. But, the rest of Scripture is more expressive. Grace, love, peace, and fellowship are only given to those in Christ.
Here are just some Scriptures.
Ephesians 1:3
“Blessed be the God and Father of our Lord Jesus Christ, who has blessed us with every spiritual blessing in the heavenly places in Christ,”
Ephesians 2:7
“so that in the ages to come He might show the surpassing riches of His grace in kindness toward us in Christ Jesus.”
Colossians 1:2
“To the saints and faithful brethren in Christ who are at Colossae: Grace to you and peace from God our Father.”
1 Thessalonians 1:1
“Paul and Silvanus and Timothy, To the church of the Thessalonians in God the Father and the Lord Jesus Christ: Grace to you and peace.
1 Timothy 1:14
‘and the grace of our Lord was more than abundant, with the faith and love which are found in Christ Jesus.’
2 Timothy 1:9
“who has saved us and called us with a holy calling, not according to our works, but according to His own purpose and grace which was granted us in Christ Jesus from all eternity,”
2 Timothy 2:1
“You therefore, my son, be strong in the grace that is in Christ Jesus.”
“I thank my God always concerning you for the grace of God which was given you in Christ Jesus, that in everything you were enriched in Him, in all speech and all knowledge, even as the testimony concerning Christ was confirmed in you, so that you are not lacking in any gift, awaiting eagerly the revelation of our Lord Jesus Christ, who will also confirm you to the end, blameless in the day of our Lord Jesus Christ. God is faithful, through whom you were called into fellowship with His Son, Jesus Christ our Lord.” 1 Corinthians 1:4-9.
“Do not be bound together with unbelievers; for what partnership have righteousness and lawlessness, or what fellowship has light with darkness? Or what harmony has Christ with Belial, or what has a believer in common with an unbeliever? Or what agreement has the temple of God with idols? For we are the temple of the living God; just as God said,
“I WILL DWELL IN THEM AND WALK AMONG THEM;
AND I WILL BE THEIR GOD, AND THEY SHALL BE MY PEOPLE. “Therefore, COME OUT FROM THEIR MIDST AND BE SEPARATE,” says the Lord.
“AND DO NOT TOUCH WHAT IS UNCLEAN;
And I will welcome you.
“And I will be a father to you,
And you shall be sons and daughters to Me,”
Says the Lord Almighty.” 2 Corinthians 6:14-18.
So, what is the importance of all this?
Some teach that God loves everyone and Christ died for everyone. Some teach that grace is given to everyone. Believers of that false teaching will be led into complacency, doubting a literal hell, because God loves everyone and gives grace to everyone in their mind. Believers of that false teaching will see no urgency nor sense in being separate or different from unbelievers or in repenting of their sin and changing their behavior. Believers of that false teaching will be led to believe that there are many different broad paths to salvation rather than one narrow way to salvation only through Jesus Christ.
Reformed Doctrine Daily Devotions 