Much has been written about Abraham Lincoln, including much about his religious faith. I will not attempt to survey all the scholarly literature here. Neither do I claim to be an expert in Lincoln. But, I do claim to be an expert in the religion of Abraham's father Thomas Lincoln. I base this claim on the fact that the elder Lincoln, a farmer-preacher, belonged to those Baptists who rejected the national Baptist denomination as it developed following the Convention in 1814. He rejected both the newly developing structure and the modernizing doctrinal changes as the Baptist mainstream evolved from a sect into an American denomination prior to the Civil War. Without bragging, I can say that I have been recognized as an expert on those Baptists who remained outside the new denominational structure. (For those interested, my book is The Formation of the Primitive Baptist Movement, based on my doctoral dissertation "Self-Definition in the Formation of the Primitive Baptist Movement as Expressed in their Three Major Periodicals, 1832-1848.")

With regard to the understanding of God, while Abraham rejected his father's politics and agrarian life, and rejected his father's religion, he still, by the end of his lifetime, came to think of God essentially in the same way his father did. (More below)

Probably the easiest window through which to view Lincoln's understanding of God by the end of the Civil War, is his Second Inaugural Address. I linked to the text in the Library of Congress in this post earlier today. For those who prefer a print version rather than handwritten, here is a link to the Fordham site. The relevant portion is:

Neither anticipated that the cause of the conflict might cease with, or even before, the conflict itself should cease. Each looked for an easier triumph, and a result less fundamental and astounding. Both read the same Bible, and pray to the same God; and each invokes His aid against the other. It may seem strange that any men should dare ask a just God s assistance in wringing their bread from the sweat of other men's faces; but let us judge not that we will be not judged. (1) The prayers of both could not be answered; that of neither has been answered fully. The Almighty has His own purposes. Woe unto the world because of offenses! for it must needs be that offenses come; but woe to that man by whom the offense cometh! (2) If we shall suppose that American Slavery is one of those offenses which, in the providence of God, must needs come, but which, having continued through His appointed time, He now wills to remove, and that He gives to both North and South, this terrible war, as the woe due to those by whom the offense came, shall we discern therein any departure from those divine attributes which the believers in a Living God always ascribe to Him? Fondly do we hope--fervently do we pray--that this mighty scourge of war may speedily pass away. Yet, if God wills that it continue, until all the wealth piled by the bond-man s two hundred and fifty years of unrequited toil shall be sunk, and until every drop of blood drawn with the lash, shall be paid by another drawn with the sword, as was said three thousand years ago, so still it must be said the judgments of the Lord, are true and righteous altogether. (3)

The God presented in Lincoln's Address is not a God who "partners up" with humanity. "The prayers of both could not be answered; that of neither has been answered fully. The Almighty has His own purposes." Rather he is a God who determines the destiny of men and nations. Offenses "must needs come" in God's determination of history, but the righteous God judges the men and nations through which they come. The severity and length of punishment is set by God: "Yet, if God will it continue, untill all the wealth . . . ." This God is sovereign and mysterious.

Such also was the view of those Baptists who remained outside the developing Baptist denomination. They held to the stern Calvinistic conception of God as expressed in the Second London Confession (written by Particular Baptists in Great Britain).

The Lord our God is . . . Almighty, every way infinite, most holy, most wise, most free, most absolute, working all things according to the councel of his own immutable, and most righteous will . . . (II.1)
God hath Decreed in himself from all Eternity, by the most wise and holy Councel of his own will; freely and unchangeably, all things whatsoever comes to passe; yet so as thereby is God neither the author of sin . . . (III.1)
Although God knoweth whatsoever may, or can come to passe upon all supposed conditions; yet hath he not Decreed anything, because he foresaw it as future, or as that which would come to pass upon such conditions. (III.2)

Or, as one of the writers of the same movement as Thomas Lincoln put it, ". . . the Lord is still the same unchanging God, whose love never ends, whose purpose never can be frustrated, who can and does work, and men nor devils cannot hinder."

I am not arguing that Abraham followed his father in all particulars of religious doctrine. I am not arguing that he even thought of God in all the same details as did Thomas. Nor am I arguing that Abraham Lincoln remained the same throughout his life. But I do think that his conception of God expressed in the Second Inaugural, at its heart, was the idea of the sovereign and mysterious God held by Elder Thomas Lincoln.