“Any ethics that needs religion is bad ethics, and any religion that tries to do so is bad religion. Of course, there are plenty of both around.”

Gil Langton's late mother, cited twice in Ch. 17, pp. 298 and 300
The Ringmaster (1991)

Section 9 : Ethical Outlook
Founding Address (1876), Life and Destiny (1913)
Context: Ethical religion affirms the continuity of progress toward moral perfection. It affirms that the spiritual development of the human race cannot be prematurely cut off, either gradually or suddenly; that every stone of offence against which we stumble is a stepping-stone to some greater good; that, at the end of days, if we choose to put it so, or, rather, in some sphere beyond the world of space and time, all the rays of progress will be summed and centred in a transcendent focus.

Source: The Principles of Ethics (1897), Part II: The Inductions of Ethics, Ch. 1, The Confusion of Ethical Thought

Source: Stride Toward Freedom (1958), pp. 28-29, New York: Ballantine Books,
Context: "The apparent apathy of the Negro ministers presented a special problem. A faithful few had always shown a deep concern for social problems, but too many had remained aloof from the area of social responsibility. Much of this indifference, it is true, stemmed from a sincere feeling that ministers were not supposed to get mixed up in such earthly, temporal matters as social and economic improvement; they were to "preach the gospel" and keep men's minds centered on "the heavenly." But however sincere, this view of religion, I felt, was too confined.
Certainly, otherworldly concerns have a deep and significant place in all religions worthy of the name. Any religion that is completely earthbound sells its birthright for a mess of naturalistic pottage. Religion at its best, deals not only with man's preliminary concerns but with his inescapable ultimate concern. When religion overlooks this basic fact it is reduced to a mere ethical system in which eternity is absorbed into time and God is relegated to a sort of meaningless figment of the human imagination. But a religion true to its nature must also be concerned about man's social conditions. Religion deals with both earth and heaven, both time and eternity. Religion operates not only on the vertical plane but also on the horizontal. It seeks not only to integrate men with God but to integrate men with men and each man with himself.
This means, at bottom, that the Christian Gospel is a two-way road. On the one hand, it seeks to change the souls of men, and thereby unite them with God; on the other hand, it seek to change the environmental conditions of men so that soul will have a chance after it is changed.
Any religion that professes to be concerned with the souls of men and is not concerned with the slums that damn them, the economic conditions that strangle them, and the social conditions that cripple them is a dry-as-dust religion. Such a religion is the kind the Marxists like to see - an opiate of the people.

Founding Address (1876), Life and Destiny (1913)
Context: The ethical element of religion has ever been its truly vital and quickening force. It is this which lends such majesty to the speeches of the Prophets, which gives such ineffable power and sweetness to the words of Jesus. Has this ethical element become less important in our age? Has the need of accentuating it become less imperative?
To-day, in the estimation of many, science and art are taking the place of religion. But science and art alike are inadequate to build up character and to furnish binding rules of conduct.
We need also a clearer understanding of applied ethics, a better insight into the specific duties of life, a finer and a surer moral tact.

Quoted in 3:439 Herndon's Lincoln (1890), p. 439 http://books.google.com/books?id=rywOAAAAIAAJ&pg=PA439&dq=%22when+i+do+good+i+feel+good%22: Inasmuch as he was so often a candidate for public office Mr. Lincoln said as little about his religious code as possible, especially if he failed to coincide with the orthodox world. In illustration of his religious code I once heard him say that it was like that of an old man named Glenn, in Indiana, whom he heard speak at a church meeting, and who said: "When I do good I feel good, when I do bad I feel bad, and that's my religion."
Posthumous attributions

Source: Christianity and the Social Crisis (1907), Ch.1 The Historical Roots of Christianity the Hebrew Prophets, p. 7
Context: The prophets were the heralds of the fundamental truth that religion and ethics are inseparable, and that ethical conduct is the supreme and sufficient religious act. If that principle had been fully adopted in our religious life, it would have turned the full force of the religious impulse into the creation of right moral conduct and would have made the unchecked growth and accumulation of injustice impossible.

Section 25
Religio Medici (1643), Part I