Orthodoxy, or “right belief,” is an essential feature of biblical Christianity. We are saved through belief in the Truth (John 14:6). Actions that please God are grounded in and informed by His truth. Scripture teaches this in many ways, including in the very structure of the biblical books themselves. For instance, the New Testament Epistles commonly place instructions for behavior after doctrinal teaching. Paul does this frequently in his letters. For instance, Romans 1–11 explains doctrines including justification, sanctification, glorification, and election. Romans 12–16 then explains how believers are to live in light of those great doctrines.
Hebrews follows a similar pattern. The first twelve chapters of the epistle do feature some practical applications, particularly the exhortation to persevere. Yet, the bulk of the material focuses on the doctrine of the person and work of Christ. Practical instructions for Christian living are found mostly in Hebrews 13.
Chapter 13 begins by telling us to “let brotherly love continue” (v. 1). This is appropriate, for love is the chief of all Christian virtues (1 Cor. 13:13). Starting with love also makes sense given the focus of Hebrews on perseverance. Christians are in this race of faith together, and if we do not love one another, we will not spur one another on to love and good works (Heb. 10:24). Without such mutual encouragement, we are more likely to turn aside from following Jesus.
Brotherly love consists in more than just feeling. It displays itself in actions. In fact, true brotherly love is costly. We must give of our own time, choosing the needs of others over our own, in order to love people well. Christian love, in fact, is willing to pay the highest price of all. Loving others rightly means being willing to lay down our lives for them all the way to the point of death if we are so called. Jesus modeled this love perfectly for us, telling us that “greater love has no one than this, that someone lay down his life for his friends” (John 15:13) before He went on to die for the sake of His people.
Although we are sinners, those who are truly united to Christ by faith have a natural love for other believers implanted in them by the Holy Spirit. If one truly loves God, then one truly loves his brothers and sisters in Christ (1 John 4:20). A persistently unloving Christian does not exist. That does not mean we will always love well, but it does mean we will always seek to grow in love for other believers.