Wayne Grudem does an excellent job of tackling this question in his book Systematic Theology: An Introduction to Biblical Doctrine.
As Grudem notes, the answer to the question "Are there degrees of sin?" may be "yes" or "no" depending on what one is referring to. In order to answer this question properly we must differentiate between two different consequences of sin: (1) legal guilt and (2) the results in life and in relationship with God.
In terms of legal guilt, or our legal standing before God, all sin is the same. Wayne Grudem explains:
In terms of our legal standing before God, any one sin, even what may seem to be a very small one, makes us guilty before God and therefore worthy of eternal punishment...Therefore, in terms of legal guilt, all sins are equally bad because they make us legally guilty before God and constitute us as sinners. (See Rom. 5:16, Gal. 3:10)1One proof text used to support this point is found in James 2:10-11: "For whoever keeps the whole law and yet stumbles in one point, he has become guilty of all. For He who said, "Do not commit adultery," also said, "Do not commit murder." Now if you do not commit adultery, but do commit murder, you have become a transgressor of the law."
So here we answer the question "Is all sin the same?" with a definitive "Yes." When it comes to our standing before God, all sin brings guilt and condemnation.
Results in Life and in Relationship with God
However, there is another side to this coin. Some sins are certainly worse than others! Wayne Grudem again explains:
On the other hand, some sins are worse than others in that they have more harmful consequences in our lives and in the lives of others, and, in terms of our personal relationship to God as Father, they arouse his displeasure more and bring more serious disruption to our fellowship with Him.The idea that there are degrees of seriousness when it comes to sin is attested throughout Scripture. Here are several examples:
1. In Ezekiel chapter 8, when God shows Ezekiel a vision involving a series of sins being committed in the temple of Jerusalem, God repeats three times, "You will see still greater abominations" (see 8:6, 13, 15).
2. Jesus implies there are lesser and greater commandments in at least two different places in Matthew. First, in Matt. 5:19 He states, "Whoever then annuls one of the least of these commandments, and teaches others to do the same, shall be called least in the kingdom of heaven." Second, in Matt. 23:23 Jesus tells the Pharisees that there are "weightier provisions of the law" such as justice, mercy, and faith.
3. Jesus stood before Pilate in John 19:11 and stated, "he who delivered Me to you has the greater sin."
Wayne Grudem sums up this section as follows:
In general, we may say that some sins have more harmful consequences than others if they bring more dishonor to God or if they cause more harm to ourselves, to others, or to the church. Moreover, those sins that are done willfully, repeatedly, and knowingly, with a calloused heart, are more displeasing to God than those that are done out of ignorance and are not repeated, or are done with a mixture of good and impure motives and are followed by remorse and repentance.2So here we answer the question "Is all sin the same?" with a definite "No." When it comes to the consequences of sin and in terms of the degree of God's displeasure, some sins are worse than others.
There is a danger that accompanies this discussion and a word of caution is in order. The danger is to think "My sin is not as bad as your sin" or "I'm basically a good person." The point of this article is not to encourage this line of thinking in any way.
The fact of the matter is that all human beings are desperate and depraved sinners who stand rightly condemned before a just and holy God. It is not about "I committed this itty-bitty, teeny-tiny sin and now God is going to send me to hell for eternity." This of course sounds extreme, makes God seem petty, and does not take into account the depravity of man, the seriousness of sin, and the holiness of God. In reality, we continually and constantly sin throughout our lifetime and apart from God's grace would remain in this willful rebellion. It is only by God's grace that anyone is saved. As Clay Jones would say, we are all born "Auschwitz enabled" and as Jesus said, "No one is good but God alone." Therefore, the proper attitude is not one of moral superiority or pride but of humility and thankfulness.
It is hard not to end with the words of Bible expositor D. Martyn Lloyd-Jones who said,
We must contemplate men in sin until we are horrified, until we are alarmed, until we are desperate about them, until we pray for them, until having realized the marvel of our own deliverance from that terrible state, we are lost in a sense of wonder, love and praise.3He went on to comment,
...our troubles are due to the fact that we are guilty of a double failure; we fail on the one hand to realize the depth of sin, and on the other hand we fail to realize the greatness and the height and the glory of our salvation…. It is because we never realize the depth of the pit out of which we have been brought by the grace of God that we do not thank God as we ought.4___________________________________________
1 Wayne Grudem, Systematic Theology: An Introduction to Biblical Doctrine (Grand Rapids: Zondervan, 1984), 501-502
2 Ibid., 502.
3 D. Martyn Lloyd-Jones, God's Way of Reconciliation: Studies in Ephesians II (Grand Rapids: Baker, 1972), 12, my emphasis.
4 Ibid., 82.