Today the term is colloquially applied to groups and individuals systematically promoting unpopular causes or denying certain crimes. Apologists are often characterized as being deceptive, or "white washing" their cause, primarily through omission of negative facts (selective perception) and exaggeration of positive ones. When used in this context, the term often has a pejorative meaning.
The term apologetics is also used in a more specific sense to refer to the study of the defense of a doctrine or belief. In this context it most commonly refers to Christian philosophical reconciliation. Christian apologetics is the effort to show that the Christian faith is not irrational, that believing in it is not against human reason, and that in fact Christianity would contain values and promote ways of life more in accord with human nature than other faiths or beliefs.
In the first centuries of our Era a number of Christian writers undertook the task of proving that Christianity was beneficial for the Roman Empire and for humanity as a whole. Also they wrote to defend their faith against attacks made by other people or to properly explain their faith. The Epistle to Diognetus, a response to the accusation that Christians were a danger to Rome, is the first known of these writings.
Following Constantine's conversion of the Roman Empire to Christianity, some Christian writers sought to explain the decline of culture and society by systematically downplaying the achievements of classical antiquity while exaggerating the persecution of Christians and the role of Christianity in society. Authors such as Paulus Orosius (History Against the Pagans) represented this tradition.
Similar traditions of apologetics developed in defense against Judaism, against Protestantism, and against rationalism. While some apologist perspectives are now largely discredited even among theologians, Christian apologetics continues to the current day in various forms (for example, the attempt to fit empirical cosmology with Biblical creation, known as creationism). G. K. Chesterton and C. S. Lewis are two of the most prolific Christian apologists in the Twentieth Century. In recent years, perhaps the most widely read Christian apologists writing in English have been Josh McDowell and Lee Strobel. Another modern apologist is Ravi Zacharias scholar of world religions from India, and author of The Lotus and the Cross: Jesus Talks with Buddha which compares Christianity with world religions and other modern movements.