“Finally”, tells us that God is directing Peter to summarize or draw all the previous teaching to its rightful conclusion. It is important for God’s people to be of one mind. We have talked of New Evangelicalism many times. We have also talked of the Ecumenical movement. These movements are of one mind in that they do not want to follow God obediently. They are nor agreed on what they should follow. They all have their particular doctrines that they hold dear. As we move along in history we see that due to the many perversions, there is less and less interest in doctrine. Even though there is an apparent unity among the false churches, they still have their own groups. They still have their particular traditions. They have their own standard of CCM music and what kind of “story telling” they will do. Some of them will have two different services; one more “traditional” service and one that is more “worldly”. They are compromised and their compromise is based on their feelings and opinions.
True saints need to be of one mind and that mind is the mind of Christ.

Philippians 2:5 Let this mind be in you, which was also in Christ Jesus:

Jesus Christ did not come to do His own will. He came to please His Father. He was willing to set aside His own glory in order to become a servant obedient unto death. He has since been exalted back to heaven and to the right hand of His Father. He is the judge of all things.
Having compassion one of another does not come without being of one mind. The goal of the true child of God is to exalt God. It is to know Him and make Him known.

Philippians 3:10 That I may know him, and the power of his resurrection, and the fellowship of his sufferings, being made conformable unto his death;

Love as brethren is also connected to being of one mind. True love is seeking to help others to know the true God. The true God is not divided.

I Corinthians 1:12 Now this I say, that every one of you saith, I am of Paul; and I of Apollos; and I of Cephas; and I of Christ.
13 Is Christ divided? was Paul crucified for you? or were ye baptized in the name of Paul?

Being pitiful and courteous is also in the context of being of one mind. Being pitiful has to do with being “well compassioned”. Being courteous has to do with being “friendly of mind”. As we work at unity we do so with a genuine care for one another. Someone that cares for another person wants that person to know the truth in a clearer way. Knowing the truth includes walking in the truth. That is what true Christians desire.
In verse 9 we are commanded not to render evil for evil. God’s children cannot be looking to get even. They are willing to accept abuse at times without seeking to “pay the person back”. Jesus set the example of this. He took abuse from the Jews and He did not fight back. He knew they were concocting lies about Him. He knew they were lost and needed to be saved.
In our text, Peter was writing to Christians. Christians need to behave like Christians. Rather than trying to get even, we need to seek to be a blessing to one another. In fact, Christians are called to be a blessing to one another. That is part of the fruit of God’s salvation. Notice that we should “inherit” a blessing. We did not earn a blessing. It is a gift of God.
In verse 10 we see that if we love life and desire to see good days, we will need to guard our tongues. We cannot be looking to slander one another. We do not speak guile. The word translated as “guile” speaks of “deceit.” Deceit is something that the ungodly are good at. Christians have been set free from that old wicked lifestyle.
In verse 11 we are reminded that we need to eschew or hate evil. The opposite of that is to do good. We need to speak peace and “ensue” it. The word translated as “ensue”, means to “pursue”. Christians are making a concerted effort to live in righteousness. We want to grow in the Lord and we want to be a light for God.

Matthew 5:16 Let your light so shine before men, that they may see your good works, and glorify your Father which is in heaven.