and to godliness brotherly kindness

2Pet 1:7 And to godliness brotherly kindness; and to brotherly kindness charity.

the Greek word translated as brotherly kindness is philadelphia; meaning fraternal affection. It is derived from philos, which is a friend. It is found 6 times in 5 verses.

Peter had used it in his previous epistle:

1Pet 1:22 Seeing ye have purified your souls in obeying the truth through the Spirit unto unfeigned love of the brethren, see that ye love one another with a pure heart fervently:

In Romans 12 Paul is laying out instructions to guide daily living in the character of God.

Rom 12:9 Let love be without dissimulation. Abhor that which is evil; cleave to that which is good. 10 Be kindly affectioned one to another with brotherly love; in honour preferring one another;

This is the character of the people of God.

Paul also instructs the Thessalonians how to walk with God, (1Thess 4:1) and brotherly love is included in that instruction as a summary of what has come before.

1Thess 4:9 But as touching brotherly love ye need not that I write unto you: for ye yourselves are taught of God to love one another.

In Hebrews 13 Paul gives similar instruction on walking in the ways of God, and he begins with brotherly love:

Heb 13:1 Let brotherly love continue.

All of this brings us back to Jesus' admonition to his disciples:

John 13:34 A new commandment I give unto you, That ye love one another; as I have loved you, that ye also love one another. 35 By this shall all men know that ye are my disciples, if ye have love one to another. (Also in John 15:12)

And to the recurring admonition in John's epistles:

1Jn 3:10 In this the children of God are manifest, and the children of the devil: whosoever doeth not righteousness is not of God, neither he that loveth not his brother. 11 For this is the message that ye heard from the beginning, that we should love one another.

1Jn 4:7 Beloved, let us love one another: for love is of God; and every one that loveth is born of God, and knoweth God. 8 He that loveth not knoweth not God; for God is love.

See also 1Jn 4:11-12 and 2Jn 1:5

Therefore, giving ourselves to brotherly love is essential in walking with Jesus and showing forth the character of God. It is essential in our response to how God has loved us that we love one another. So add to your godliness brotherly love, the spirit of God that is in you will teach you to love one another in the same way that Jesus loved us.

Appendix

Paul's Instructions leading up to brotherly love:

1Thess 4:1 Furthermore then we beseech you, brethren, and exhort you by the Lord Jesus, that as ye have received of us how ye ought to walk and to please God, so ye would abound more and more. 2 For ye know what commandments we gave you by the Lord Jesus.

3 For this is the will of God, even your sanctification, that ye should abstain from fornication: 4 That every one of you should know how to possess his vessel in sanctification and honour; 5 Not in the lust of concupiscence, even as the Gentiles which know not God: 6 That no man go beyond and defraud his brother in any matter: because that the Lord is the avenger of all such, as we also have forewarned you and testified. 7 For God hath not called us unto uncleanness, but unto holiness. 8 He therefore that despiseth, despiseth not man, but God, who hath also given unto us his holy Spirit.

Another discourse by Paul on brotherly love:

Rom 13:8 Owe no man any thing, but to love one another: for he that loveth another hath fulfilled the law. 9 For this, Thou shalt not commit adultery, Thou shalt not kill, Thou shalt not steal, Thou shalt not bear false witness, Thou shalt not covet; and if there be any other commandment, it is briefly comprehended in this saying, namely, Thou shalt love thy neighbour as thyself. 10 Love worketh no ill to his neighbour: therefore love is the fulfilling of the law.

Note that this is often placed as an opposite to sin