The exhortation to look within would logically mean that people should look for evidence of God’s activity within their minds, their values, and their religious experience. In the canonical Gospels, Jesus never over-emphasizes one of these three at the expense of the other two. One is to love God with mind, heart (one’s deepest values), and soul (which manifests in action). The notion of a kingdom within does not speak of an imbalance in the spiritual life, but of a profound balance between thinking, feeling, and doing. One thinks about the will of God, hungers and yearns for God, and does the will of God (Matt 5:6; 7:21; 21:31; Luke 8:21; 10:27).
Inwardness is important in all the Synoptic Gospels. What characterizes a person is the “treasure” or “light”—or “evil”—within (Luke 6:45; 11:35–36; Matt 6:23; 12:34–35; Mark 7:15, 20). “Treasure” refers to one’s deepest desires and values, and spiritual desire shapes destiny: “Where your treasure is, there your heart will be also” (Luke 12:34). We are to seek “treasure in heaven” (Luke 12:33; 18:22; Matt 6:20; 19:21; Mark 10:21).
A divine indwelling also occurs in John: Jesus is within the believer: “I abide in you”; “I in them”; “the love . . . in them” (John 15:4; 17:23; 17:26). “The Spirit of Truth . . . will be in you” (John 14:17). All these sayings use ἐν, a preposition related to ἐντός, as do passages in the Johannine and Pauline epistles that speak of Christ within (1 John 3:24; 4:13; Rom 8:10; Gal 2:20; Col 1:27; 3:11). This inwardness has profound results. All the streams of the NT teach that people can “discern what is the will of God” (Rom 12:2; cf. Col 1:9; Eph 5:17; Jas 1:25), and then actually “do the will of God” (John 7:17); in fact, a follower of Jesus is defined as “whoever does the will of God” (Mark 3:35; cf. Matt 7:21; 12:50). One acts out of the treasure of the heart, and that can be “good treasure” (Matt 12:35; Luke 6:45).
Despite the emphasis of many theologians, the historical Jesus was not pessimistic about human nature. People can actually love God “with all your heart” (Luke 10:27). People can be “pure in heart” (Matt 5:8). The Johannine tradition does emphasize a certain inwardness of spiritual experience—“The Holy Spirit . . . will teach you everything” (John 14:26; cf. 1 John 2:27)—but the Spirit-within is a central Lukan and Pauline theme, and doing the will of God is a central Matthean and Markan theme.
The Apostle Paul certainly has a concept of inwardness: “our inner nature is being renewed day by day” (2 Cor 4:16). The believer has the “mind of Christ” (1 Cor 2:16); the transformed mind discerns the will of God (Rom 12:2). In fact, we will “be conformed to the image of his Son” (Rom 8:29; cf. Phil 3:21; 1 Cor 15:49), and will be “transformed into the same image” (2 Cor 3:18; cf. Col 3:10). For teachings on transformation, the Pauline literature is the richest in the NT, yet we see them elsewhere as well: we “may become participants of the divine nature” (2 Pet 1:4; cf. 5:4); “we will be like him” (1 John 3:2); “will shine like the sun” (Matt 13:43); and “stand without blemish” (Jude 24).
The notion of an indwelling divinity, or at least a capacity for individual perception of divinity, is not alien to the OT, either. “The human spirit is the lamp of the Lord, searching every inmost part” (Prov 20:27). “Truly it is the spirit in a mortal, the breath of the Almighty, that makes for understanding” (Job 32:8). The Lord spoke to Elijah as “a still small voice” (1 Kgs 19:12 RSV). These theological points suggest an anthropological one: “There is something divine in man, or he could know nothing of God.”9 The notion that people have God-receptive capacities or spiritual faculties, often called “natural theology,” is a time-honored thread in Christian thought, though often attacked.
Still, the kingdom is not separable from Christ. The NT affirms Christ as not only the revealer, but the bringer, of the kingdom. His healings and exorcisms reveal the kingdom: “if it is by the Spirit of God that I cast out demons, then the kingdom of God has come to you” (Matt 12:28; cf. Luke 11:20). Many scholars who resist the notion of an inward kingdom will allow that such texts—and not just the “eternal life” passages in John—speak of “realized eschatology,” the kingdom present here and now. The Synoptics affirm that the kingdom is “near” (Matt 3:2; Mark 1:15; Luke 10:9).
Jesus means several things by “the kingdom of God”: something that will come “with power” and will be “seen” by people (Mark 9:1), something that grows dramatically yet without our control (Mark 4:26–32), the company of the faithful in the afterlife (Matt 21:31), something that exists in a community (Matt 21:43), and—Yes!—something that exists within each believer (Luke 17:21, and many mentions of having “light” or “love” or “treasure” within, to being pure in heart or loving God with all one’s heart).
Be Perfect
For anyone who worships God and thinks of the character of God as embodying all value, “be perfect, therefore, as your heavenly Father is perfect” (Matt 5:48) is a command to take on the divine character. Aspiring for the divine nature is declared a legitimate goal, although it may be a goal that is never fully reached, a goal that perennially draws us on—in which case, “be perfect” would signify “be ever-perfecting.”
The saying should astound us. Here, at the end of the first section of the Sermon on the Mount, perfection is commanded. By commanding perfection, Jesus suggests the necessity—and possibility—of human transformation, a profound correcting of that which is imperfect, even within this lifetime. This causes enormous difficulties for theologians who assume that all humans are thoroughly depraved and sinful, even after being saved. The verse is equally painful for secularizing critics who want to de-fang it, to suppress the suggestion of divinization. Many scholars want to see the saying as referring to a perfecting of discipleship. This is legitimate, but not if it is used to stifle the transcendent aspect. How could a command to become like “your heavenly Father” not have a transcendent meaning?
At the very least, the saying indicates that God has a plan for perfecting people, in synchrony with earlier hopes about “God who fulfills his purpose for me . . . The Lord will fulfill his purpose for me” (Ps 57:2; 138:8). God yearns to complete what he has started: “you would long for the work of your hands” (Job 14:15). The perfection saying promises the fulfillment of God’s aspirations for us, as much as of our aspirations toward God. If there is an answer to our spiritual longings for understanding, reconciliation, and communion, surely there is also an answer to the Father’s intention to make us part of a heavenly family; his will is done in heaven (Matt 6:10). Deification may be hinted at here and elsewhere in Matt 6: “your Father who sees in secret will reward you . . . Store up for yourselves treasures in heaven . . . your whole body will be full of light . . . will he not much more clothe you—you of little faith?” (6:6, 18, 20, 22, 30). Rewards, treasures, light, and being “clothed”—might these not speak of transformations that await us?
One question that has preoccupied exegetes is the meaning of τέλειος. “Perfect” is the most common translation, but “complete,” “mature,” and “whole” are possible. In what sense are believers to be perfect or complete? Perfect in devotion? In wisdom? In love? It soon becomes apparent that these questions will need to be examined in light of the passage in which it occurs. Should it be treated as the summarizing statement of the first section (chapter) of the Sermon on the Mount, or as the culmination of a shorter passage (Matt 5:38–48) that speaks of loving one’s enemies (5:44) and of being children of God (5:45)?
Let us treat the immediate context first.