Little sins - Is there such a thing? One author states categorically, "There are no 'little' sins, for they are all equally evil." Is he right?

Well, I both agree and disagree. (How's that for a political response?) The context of the statement should have helped you, because the author should have explained how he meant it. That he did not do that is unfortunate. Consider:

1) If we are talking about how much sin it takes to separate us from a holy God (Isa. 59:2), or how much sin it will take to keep us out of heaven, then any sin (unless one has put his faith in Christ) will do, even the teeny tiniest sin. The prophet Habakkuk says to God, "You are of purer eyes than to behold evil, and cannot look on wickedness" (Hab. 1:13). Because God is perfect, and heaven will be a perfect place, even the slightest sin would spoil it. It only takes one sin to make a sinner.

That's how it was for Adam and Eve (Gen. 2:17; 3:6). Think of God's holy standard as a chain linking Adam to Him. He did not need repeated disobedience, or doing many wrong things, thus breaking many links to sever the connection and "fall." Only one sin did it. And James says, "Whoever shall keep the whole law, and yet stumble in one point, he is guilty of all" (Jas. 2:10).

2) That being said, the Bible does seem to indicate that there are degrees of evil. Apart from Scripture, logic suggests that there are some sins which have a more profound and lasting effect on others. (The sin of murder is a good example. A life on earth is ended, and cannot be restored. Stealing my neighbour's hammer is different in that respect!) In this case, we are dealing more with the temporal consequences or effects of sin. And God does seem to take that into account.

Note, for example, that not all sins were punishable by death for those who lived back under the Law. And there are other examples of differences being made. The Mosaic Law made a distinction between "unintentional" sins and "presumptuous" sins--those committed in ignorance or accidentally, versus sins involving a purposeful rebellion against God (Num. 15:27-31). Then "the blasphemy against the Holy Spirit" seems to be put in a special category all its own (Matt. 12:31-32). (I trust mentioning this won't get us off onto a difficult rabbit trail!)

Also, the love of the Lord Jesus for little children, and His desire to protect them, seems to make sinning against them especially revolting to the Lord. "Whoever causes one of these little ones who believe in Me to sin, it would be better for him if a millstone were hung around his neck, and he were drowned in the depth of the sea" (Matt. 18:6). And Romans 1:18-32 surely reveals a progression as to the depth and pervasive effects of wickedness.

3) These distinctions apparently affect the degree of punishment beyond this life. I believe Dante was right about that. In his Inferno, published in 1308, he describes nine circles of hell, one inside the other, and each involving greater punishment than the one previous, with Satan at the very centre. Those consigned there are placed according to the degree of their wickedness, with each circle's sinners punished for all eternity in a fashion befitting his crimes.

We get a hint of what is to come in the fact that some demons (fallen angels), and including Satan (I Pet. 5:8), have been allowed to roam free for a time, while others did something so wicked (or so dangerous to human beings) that "God did not spare the angels who sinned, but cast them down to hell, and delivered them into chains of darkness, to be reserved for judgment" (II Pet. 2:4; cf. Jude 1:6).

Then, seeing a vision of the Great White Throne, where all the unsaved of all the ages will be finally judged and condemned to hell (Rev. 20:11-15), the Apostle John says, "books were opened." The unsaved condition of these individuals is established by the fact that their names are not found in the Lamb's "Book of Life." But God's Word says the other books will be used to assess their works. Why? I believe what is found in them will relate to the degree of punishment each person faces in eternity.

So, yes and no. All sin is sin. But not all sins are equal in certain respects.