Dennis E. Johnson
Like Israel, we need a mediator whose voice God has heard, and hears. We have that mediator in our Lord Jesus Christ.
God, in his providence, designed all the events of the first century Church so that various crises came up in churches when apostles couldn't get there soon enough, or in person. So they wrote letters.
When courtesy becomes cruelty.
God is our shield and our great reward.
In his epistle, John exhorts us to follow God's commandment of loving one another.