Christianity, the most widely distributed of the world religions, having substantial
representation in all the populated continents of the globe. Its total membership may
exceed 1.7 billion people.
Like any system of belief and values—be it Platonism, Marxism, Freudianism, or
democracy—Christianity is in many ways comprehensible only “from the inside,” to
those who share the beliefs and strive to live by the values; and a description that would
ignore these “inside” aspects of it would not be historically faithful. To a degree that
those on the inside often fail to recognize, however, such a system of beliefs and values
can also be described in a way that makes sense as well to an interested observer who
does not, or even cannot, share their outlook.
Doctrine and Practice
A community, a way of life, a system of belief, a liturgical observance, a tradition—
Christianity is all of these, and more. Each of these aspects of Christianity has affinities
with other faiths, but each also bears unmistakable marks of its Christian origins. Thus, it
is helpful, in fact unavoidable, to examine Christian ideas and institutions comparatively,
by relating them to those of other religions, but equally important to look for those
features that are uniquely Christian.
The instruction and exhortation of Christian preaching and teaching concern all the
themes of doctrine and morals: the love of God and the love of neighbor, the two chief
commandments in the ethical message of Jesus (see Matthew 22: 34-40). Application of
these commandments to the concrete situations of human life, both personal and social,
does not produce a uniformity of moral or political behavior. Many Christians, for
example, regard all drinking of alcoholic beverages as sinful, whereas others do not.
Christians can be found on both the far left and the far right of many contemporary
questions, as well as in the middle. Still it is possible to speak of a Christian way of life,
one that is informed by the call to discipleship and service. The inherent worth of every
person as one who has been created in the image of God, the sanctity of human life and
thus of marriage and the family, the imperative to strive for justice even in a fallen world
—all of these are dynamic moral commitments that Christians would accept, however
much their own conduct may fall short of these norms. It is evident already from the
pages of the New Testament that the task of working out the implications of the ethic of
love under the conditions of existence has always been difficult, and that there has, in
fact, never been a “golden age” in which it was otherwise.
Almost all the information about Jesus himself and about early Christianity comes from
those who claimed to be his followers. Because they wrote to persuade believers rather
than to satisfy historical curiosity, this information often raises more questions than it
answers, and no one has ever succeeded in harmonizing all of it into a coherent and
completely satisfying chronological account. Because of the nature of these sources, it is