Paul uses pleading tone: "I beseech you" is an invitation, not a command. He addresses them as brothers. As Christians we are to consider each other as family members.
Because God has extended his mercy to us, we have the opportunity to worship him by living in a sacrificial manner toward him, which is, in fact, our reasonable expectation.
Paul urges us not to conform ourselves to the standards of the world, but to be transformed by the renewing of our minds so that we prove what is good and acceptable and perfect, the will of God.
In verses 3 through 8 he deals with blessings and ways to serve the members of the family we form in God's love.
We are to live in humility and generosity toward one another. He emphasizes the unique attributes and talents individuals among us possess and the way they are to be used and cherished.
He calls us to be free of hypocrisy and to be cheerful.
In verse 9 he returns to the emphasis on familial love among the Brethren.
It is important that we not be lazy or negligent in business.
In verse 13 he points out the need to attend to the needs of those who are poor and without resources.
Then he shifts to the attitude we should have toward those who persecute us: We should pray for them and not heap curses and intolerance on them.
Share in the joy and sorrow of all.
The final words of the chapter are directed toward those who are our enemies. Don't return evil for evil. Live in peace with all if you can.
Don't take vengeance because that belongs to God.