If, as Paul writes, Christian freedom is not licentiousness or legalism (Gal. 5:16–21), what does it mean to “walk by the Spirit”? The answer, the apostle demonstrates, is seen in our manifestation of the Spirit’s fruit (vv. 22–24).
Let us begin with two observations about Paul’s use of the fruit metaphor itself. First, there is a degree of inevitability with the word fruit — well-nourished apple trees inevitably produce apples. Likewise, believers, as those who abide in Christ through the Holy Spirit, cannot help but yield lives in which the Spirit’s fruit predominate, not evil works (John 15:1–11; Gal. 5:19–21). In so doing, they fulfill the vocation given to Israel (Isa. 5:1–4). Second, the Greek word karpos or “fruit” in Galatians 5:22 is singular. Paul lists many different virtues in verses 22–23, but there is a unity to them. The “fruits” of the Spirit are one; thus, none of them is optional. John Calvin comments that only those who bear all of the fruit, to one degree or another, prove themselves to be in Christ.
We see evidence for the unity of the fruit in that Paul places love, the only quality to appear in all the other New Testament listings of spiritual traits (see 1 Cor. 13:13; 1 Tim. 4:12; 2 Peter 1:5–7), at the top of his list (Gal. 5:22). Commentators both ancient and modern agree that love is the root of all of the fruits in Galatians 5:22–23; in fact, they are manifestations of love, the chief Christian virtue, the one that will last forever (1 Cor. 13:8). The church father Jerome remarks, “Without love other virtues are not reckoned to be virtues. From love is born all that is good.” (ACCNT vol. 8, p. 85). God is love (1 John 4:8), and to imitate Him as we walk by the Spirit is to love others.
Paul expands upon these other fruits in the rest of Galatians, and in our study of the remaining parts of the epistle we will have the opportunity to look at them more closely. Note today that the apostle includes joy in his list (Gal. 5:22). Martin Luther writes that this proves that God “hates comfortless doctrine, heavy and sorrowful cogitations, and loves cheerful hearts.” Theology must always end in doxology — the joyful praise of our Creator; otherwise, we have not truly studied the things of God.