As you look at the order that Peter wrote this you can't have one without the other to support. Without knowledge you wouldn't understand what areas you need to build up in self-control. Without self-control it would be hard to have perseverance in hard times.
Let's look at the layer of kindness which is right below the roof of love. Just below the roof is the rafters. They are the support for the roof and go beyond the building. Yet they are supported by the building. Once the roof is put on over the rafters the building itself is protected on the inside from the outside storms that come along.
Our rafters is brotherly kindness. Peter tells us that we have to be diligent in building this spiritual building in our lives. It is easy to be kind to someone we don't know, even if it is a not so random act of kindness but something you planned to do that day. Brotherly kindness is harder and takes much more of an effort.
Like in any family there are differences and these can make it hard to get along with people. Those of us that have siblings know what it is like, when you get in a fight with you sibling and your mom tells you to say sorry. You quickly and short snap, "Sorry". The next thing you hear from you mom, or as a mom you have said, "Say it like you mean it." This example I got from my pastor this Sunday. He wasn't talking about brotherly kindness but it fits so well as to how hard it is to extend that kindness beyond our comfort of the walls.
As the Church, in a whole we have a problem extending brotherly kindness to those who belong to a different denomination, church, even to those that my go to our church but have hurt us some how. By extending brotherly kindness to those that we may not see eye to eye with is building the frame work to extend God's love to.
First Call's song "Undivided", shows the reason to extending brotherly kindness is not as hard as we make it to be.
We may worship different ways
We may praise Him
And yet spend all of our days
Living life divided
But when we seek Him with open hearts
He removes the walls we built
That keep us apart
We trust Him to unite us
In our hearts, we're undivided
Worshiping one Savior, one Lord
In our hearts, we're undivided
Bound by His spirit forevermore
Undivided
It doesn't matter if we agree
All He asks is that we serve Him faithfully
And love as He first loved us
He made us in His image
image: http://static.urx.io/units/web/urx-unit-loader.gif
And in His eyes, we are all the same
And though out methods they may be different
Jesus is the bond that will remain
In our hearts, we're undivided
Worshiping one Savior, one Lord
In our hearts, we're undivided
Bound by His spirit forevermore
Undivided
In our hearts, we're undivided
Worshiping one Savior, one Lord
In our hearts, we're undivided
Bound by His spirit forevermore
Undivided