Conversion refers to two different kinds of “turning” to God: the change of allegiance from one religion (or branch of a religion) to another; and the movement from lack of faith or purely formal faith to commitment, or, with a more moral emphasis, from a life of sin to one of attempted virtue in obedience to God. In trying to understand conversion in the Bible, it is temping to find modern individualism operating in situations where matters of group loyalty were in fact more salient. It is also easy for the modern reader to see certain biblical episodes as conversions when they are better taken as calls by God to new roles.

The complex play of these factors may be illustrated by several examples. The stories of God's encounters with figures such as Abraham (Gen. 12; 17), Jacob (Gen. 28.10–17), and Moses (Exod. 3) may, in their origins, reflect transfers of tribal allegiance to a new deity, though in their final form they appear as calls to deeper loyalty or to a new phase in the relationship between God and his people or a particular leader. Similarly, stories such as that in Joshua 9 describe the adherence of whole groups to Israel's deity, Yahweh, inspired by what appear to us to be political and social motives. In the much later setting of the New Testament, there is evidence of people moving from other religions to Judaism, just as they moved to the Christian movement (see references to proselytes, Acts 2.10; and to gentiles on the edge of Judaism, such as Cornelius, Acts 10).

The story of Isaiah of Jerusalem (Isa. 6.1–8) is best seen as a call to a more profound allegiance to Yahweh. While it is wholly personal in its reference, it nevertheless places Isaiah in a well‐authenticated tradition of holy individuals, among whom Samuel, Elijah, and Elisha are in many ways comparable earlier examples. Such figures, themselves “converted” in a charismatic act, become charismatic leaders, stirring the people, on the basis of their God‐given authority, to military zeal (as in the case of Samuel or Saul), to faithfulness to Yahweh as opposed to other gods (Elijah and Elisha), or to cultic and moral purity (Isaiah, Amos, Hosea, Jeremiah). It is noteworthy that in the story of Isaiah's “conversion” a moral element is explicit (6.5) as God's purity is brought home.

The so‐called conversion of Paul (described in Acts 9; 22; 26; and more intimately in his own words in Gal. 1.15–16) is in many ways comparable to such prophetic calls; indeed, “call” (Grk. kaleō) is Paul's own most characteristic word for the summons of God both to himself and to others (1 Cor. 1.1–2; 7.17–24). It is certainly not conversion in the sense of a move from irreligion to belief, or from a life of vice to one of virtue (Phil. 3.6), nor was it perceived by Paul as a move from one religion to another; there is scarcely any sign that Paul saw the new faith as other than the true Judaism, the realization of God's plan for his people (Rom. 9–11). Rather, it was a call from God to serve as emissary (apostle) of Jesus Christ, whom God had sent for the purpose of drawing Jews and gentiles alike into his people.

With deep‐seated origins in stories of transferred tribal allegiance and the rise of charismatic military and political leaders, there emerges in the prophetic literature—whose attitudes so deeply color the final form these stories take—a pervasive sense of God's call both to individuals and, through their activity, to his people, a call for a new loyalty to him and for a more profound moral obedience. It is evident in the preexilic prophets' summons to Israel to “turn” (See Repentance), as well as in the later optimistic promise of restoration in Second Isaiah (Isa. 40–55).

This tradition of God's urgent call to turn again reaches new intensity in the ministry of Jesus. In the light of the coming kingdom of God, Jesus summons people to unconditioned and simple (Matt. 18.3) allegiance to God, brushing aside competing claims such as wealth (Mark 10.17–31) and family ties (Mark 1.16–20; Matt. 8.21–22; Luke 14.26). The outcome of his summons is salvation, seen in terms not only of the coming new age, but also of forgiveness and healing here and now. It is likely that many of the Gospel stories of healings by Jesus and other encounters with him were told and heard in terms of conversion responses to Jesus' call. It is noteworthy that precisely the same Greek words, “Your faith has saved you,” are used in relation to an act of forgiveness (Luke 7.50) and an act of healing (18.42). This activity is consciously set against the prophetic background (Luke 4.18–21), as indeed is the language in which the subsequent preaching of early Christian leaders is described (Acts 9.35; 11.21; 14.15; 26.18, 20).

Although the element of repentance and “turning” is present in much biblical material concerning people's coming to God's service, the element of “call” is more fundamental; this is clear in the portrayal of Jesus' own ministry as inaugurated by such an episode (Mark 1.9–11). Here, charisma and divine recognition are bestowed with a view to his acting as God's agent.

Adopting a perspective more keenly aware of the social realities of the world of the first century CE, we may note that in Palestine the appeal of Jesus was akin to that of a number of leaders of reform and renewal within Judaism of that period; note especially John the Baptist. In Greco‐Roman society, where the Christian movement was unique among these Palestinian groups in its success in moving beyond its original setting, both the appeal and the process of “joining” were different. It is likely that a number of those attracted were people who, in one respect or another, were on the margins of society or felt themselves to be so. As Acts indicates, a number were “God‐fearers,” gentiles already attracted to Jewish synagogues but never able to be more than fringe members. Others may have been aliens living far from their native lands; and the power to attract women may have been linked to aspirations in earliest Christianity toward gender equality (Gal. 3.28).

Such changes of religious alliance were not common in the ancient world: the open, tolerant, and undemanding nature of Greco‐Roman religion made them largely incomprehensible. But there was some parallel in decisions to adhere to philosophical groups, a decision that might involve a measure of commitment to a specific way of life, and in the adoption of some of the mystical paths available within the religious spectrum. In any case, the strong group identity of the Christians must have been a powerful force; and if we ask what it felt like to join the Christians in a Greek city, then the provision of a “home,” centered on Christ, was a major factor, not unlike the similar provision which might be found in the synagogue or in the many guilds or clubs that abounded in city life.

J. L. Houlden