Consider the example of the slave, who served his master with love. Only a sense of the love of Christ could produce such a love for one another. Our love is often cold, and unfortunately the world sees that. But here is an example of love that leaves the world stunned. Beloved in Christ, let us love like this—a genuine love that flows from the love of Christ.
To wage good warfare as Christians, we need encouragement (from God's word), the right equipment (faith and a good conscience), and knowledge about our enemies (how they became enemies, where they're headed, and the hope for them) if we hope to succeed.
The Gospel at it's core really is simple. And it requires a simple, though significant, response.