Christian Theology - a study guide based on Thomas P. Rausch's Catholicism in the Third Millennium (2003)
Wikipedia: Christianity - very comprehensive, but caution: some portions are excellent, others are very poorly written!
What is Christianity?
Christianity is one of the three main “Western” or “Abrahamic” or “Monotheistic” religions (along with Judaism & Islam). As the largest religion in the world today (over 2 billion adherents, or about 1/3 of the world's population), Christianity is based on the belief that Jesus of Nazareth, a man who lived about 2000 years ago in the land of Israel, is the “Christ” (“Messiah”) and the “Son of God.” Beyond that, however, there is huge variety in specific beliefs and practices.
Like most other world religions, Christianity has several core aspects that can be studied, as outlined below:
I) History and Development; II) Core Beliefs and Practices; III) Structures & Regulations
Paul and other Christian missionaries to the Gentiles (throughout the Eastern part of the Roman Empire)
Christianity gradually spreads & grows, but is sporadically persecuted by Roman authorities
Persecutions end with the Edict of Milan and the conversion of Emperor Constantine (312 CE)
Core Christian Tradition (and many local traditions) are passed on & adapted over 2000 years
Christians debate, disagree, and divide from the start; as evidenced even within the NT (see Gal 1-2; 2 John; 3 John; etc.)
Great Schism (1054) - long-growing tensions finally lead to a definitive split between Eastern (Greek) and Western (Latin) Christians
Protestant Reformation (begins 1517) - Martin Luther, John Calvin, and many others "protest" against abuses in the Roman Catholic Church, and end up forming separate churches and denominations, more and more over time
Latin moresand Greek ethosboth mean "custom" (how a group of people customarily live and act).
Thus, both "ethics" and "morals" have the same meaning, and could be used interchangeably;
but in practice, "morals" often refers to sexual matters, while "ethics" refers to everything else:
Basic Moral Imperative - "Do good & avoid evil" (basic human philosophy; Luke 6:27-36; Rom 12:21; 13:3-5; 1 Peter 3:8-17)
Decalogue - Ten Commandments, from Exod 20 & Deut 5, partially quoted in Matt 5:17-48; Mark 10:19 (par. Matt 19:18-19; Luke 18:20
Greatest Commandment - "Love God; and Love others as yourself" (Deut 6:4 & Lev 19:18); as quoted in Mark 12:29-31 (par. Matt 22:34-40; Luke 10:25-28; cf. Rom 13:9-10)
More Love Commands - "Love your enemies" (Matt 5:43-48; Luke 6:27-35);
"Love one another as I have loved you" (John 13:34; 15:12-17; Rom 13:8; 1 Thess 4:9; 1 John 2:7-10; 3:23; 2 John 5)
Golden Rule - "Do unto others as you would have them do unto you" (Matt 6:12; par. Luke 6:31);
related to this is "forgiving others" (Matt 6:12-15), "not judging others" (Matt 7:1-5),
and in general striving to be and act like God (Matt 5:48; Luke 11:2-4; cf. Lev 11:44-45).
Conscience - priority of individual conscience; but obligation to develop an "informed" conscience
Principles of Sexual Morality: dual purpose of sex; consistent ethic of life; central role of family; mutuality in human relationships
Principles of Social Ethics: dignity of each person; preserve the common good; work, participation, property; care of the poor/needy