Christian humanism refers to two related concepts. In one usage, the term is applied retrospectively to sixteenth century Chrisitian thinkers who were Renaissance humanists (medieval scholars involved in recovering the humanities traditions of Classical Antiquity). Another is "modern" Christian humanism, which is 20th century coinage emphasising the importance of humanitarian principles within a Christian moral framework, such as human dignity, individual freedom, and the pursuit of happiness.

It is not to be confused with modern humanism, which refers to philosophies that assert the primacy of human values and frame of reference over gods, theology, or religion in general. It should also not be conflated with religious humanism, which refers to a nontheistic movement that practices humanism in congregational structures.

While the Renaissance humanist movement was largely about the rediscovery of pre-Christian literature and moral philosophy, scholars such as Charles Nauert argue that a subset of European humanist scholars were unafraid to discuss their own religious positions in relation to the classical literature, marking them out as "Christian humanists", in contrast from others in the movement "who just happened to be religious":

made a connection between their humanistic teaching and scholarship on classical languages and literature, on the one hand, and on the other hand, their study of ancient Christianity, including the Bible and the Church Fathers... Even more important, they associated their scholarly work (classical as well as biblical and patristic) with a determination to bring about a spiritual renewal and institutional reform of Christian society. That connection between their scholarly efforts and their longing for spiritual and institutional renewal is the specific characteristic that distinguishes "Christian humanists" as a group from other humanists who just happened to be religious.

Modern theological conceptions of Christian humanism are in part inspired by this view, although they differ on whether Christian humanism is a distinct movement within Christianity or a component aspect of Christianity in general. Theologians such as Jens Zimmerman make a case for the concept of Christian humanism as a cogent force throughout the history of Christianity. In Zimmerman's account, humanitarian and rights-oriented philosophies emerged organically from the Christian doctrine that God, in the person of Jesus, became human in order to redeem humanity, and from the further injunction for the participating human collective (the church) to act out the life of Christ.

Renaissance historian Margaret Mann Phillips says that this subset of Renaissance scholars argued that the most appealing aspects of moral philosophy and art from pre-Christian Europe were in fact themselves a direct product of the Christian God. As such, the basis of Christian humanism was "the belief that all that is good comes from God, and the pre-Christian ages were inspired by Holy Spirit for his own purposes."

The term Christian humanism was popularised in the 20th century, after the emergence of the modern humanist movement, which is non-religious (sometimes referred to as "secular humanism" in the United States). This movement argues that humanism is the idea that human beings are the ultimate source of moral value and moral decisions, and therefore is incompatible with theistic beliefs or claims that moral rules are divinely ordained. To this end, humanist writers have opined that the term "Christian humanism" lacks coherence, or has in reality been used to unconvincingly arugue for the "exceptionalism" of Christianity in comparison with other religions or humanism, or even that it deliberately "co-opts" the appealing aspects of humanism (such as the fruits of modern social progress) in the name of Christianity. An example of this would be Zimmerman's claim that "common humanity, universal reason, freedom, personhood, human rights, human emancipation and progress, and indeed the very notion of secularity... are literally unthinkable without their Christian humanistic roots."

Scholars since the 18th century have agreed that some sort of change took place in Western European civilization in the period from 1300 to 1600. However, the extent and nature of this change have been widely debated. Some have seen the period as one in which a radically new sense of the world and humanity emerged, whereas others have seen instead the gradual development of ideas that had long been current. Nevertheless, there are elements in Renaissance thought that recur frequently in comparison to earlier centuries. In the Middle Ages, people typically yielded some of their identity to corporations—the church, the state, the feudal society, the guild, the university, and the monastic order. With the Renaissance came an increased sense of individuality and a celebration of uniqueness and individual self-determination. The literature of the period is filled with statements such as the following about the dignity, excellence, rationality, and power of individual human beings: