Truly this depends upon what you are asking? With respect to what are you asking the question?
If it is with respect to the law of God, then yes. All sins are damning from the white lie to the adulterer and murderer. Each and every sin separates us from God and judges us unworthy of eternal life. We read in John 8.34 that
everyone who commits a sin is a slave to sinand from Psalm 14.3,
they have all turned aside; together they have become corrupt; there is none who does good, not even one.
Perhaps you ask this in respect to the judicial law of our government? Here the answer is shows that not all sins are equal. For when you tell a white lie and sin, the police do not come and give you the death penalty. Whereas if you commit a crime, a sin, which is considered bad enough, the death penalty may be given. And there is a wide variety of punishments in between depending upon how severe the crime has been judged.
It is pretty well understood that whatever you do sinfully, there will be some punishment for it, whether that be before God or before men. You could say that a problem occurs today when the free given grace of Jesus is given in the picture and also when the kingdom of the left (the government) is not checked in its foray into the kingdom of the right (the kingdom of God).
When the grace of Jesus is given, all sins are forgiven. He paid for all sins, and was our propitiation to the Father. As we read in Matthew 20.28 that the Son of Man came
to give His life as a ransom for many.and from Roman 3.25 that the grace of Jesus Christ was
put forward as a propitiation by His blood.And with respect to this. It can often be sorely abused. For example, if a man and woman are living in sexual immorality, they may justify the fact that they are living that way by saying (In good straw man fashion) that Christ has absolved them from all that. "What then," they would ask, "is the difference between what they are doing and what a person who tells a white lie often enough? A sin is a sin and all are guilty for them, and Jesus Christ has die for all!"
And the secular laws haven't helped either. As "we" (Christians who think our nation was founded on Christian principles, I exclude myself from this group) have decided that the Ten Commandment belong in the courtroom, it has back flowed into Christianity. Thus, the consequences become such that if there is no legislation on a certain action, then it must be permissible. (I thank David F. Wells for his discussion in his book Losing Our Virtue: Why the Church Must Recover It's Moral Vision for my conclusions) Thus, the same couple living in sexual immorality can also say, well there's no law (secular) against it, so it isn't wrong.
And thus the grace of Christ and the secular laws have given us a problem... it seems.
But, what is missing? What are we leaving out of the picture? The answer is faith. Saving faith and a "fear, love and trust in God above all things" is missing from the picture. What we are dealing with here is the battle against unbelief, which is at the heart and center of Christianity.
It is unbelief which leads a person to no longer fear the consequences of breaking the law. It is unbelief that looks for reasons to circumvent or ignore the law of God. It is unbelief that allows that couple to say it is alright to continue living in sin.
The Law of God remains true and clear and its threat of eternal punishment is there for all who choose darkness and unbelief. Thankfully, the Gospel of our Lord Jesus Christ, the message of the forgiveness of sins given to us, is the combatant against this unbelief. For, it brings light to the darkness and life to the dead and unbelieving heart. It drowns the Old Adam and proclaims upon us the righteousness of Christ, giving us new hearts to accept and fulfill the law of God with a willing spirit.
Yet, the hard question still remains if all sin is forgiven, what is the difference between a white lie and living in sexual immorality? Deitrich Bonhoeffer in his Ethics has a very good quote that I think is spot on. He writes,
One sin, then, is not like another. They do not all have the same weight. There are heavier sins and lighter sins. A falling away is of infinitely greater weight than a falling down. The most shining virtues of him who has fallen away are as black as night in comparison with the darkest lapses of the steadfast.Again, it comes back to unbelief. Those who are living in sin are in a cosmic battle for their souls. The devil is guiding them by the hand into unbelief and damnation. He teaches them to treat the Word of God, especially the threat of condemnation, as though it were inconsequential. Thus, the couple living in sin, accepting of that sin, are on the road of unbelief. But again, thanks be to God. For by His great mercy He has given us His Word that we might have eternal life. This Word is good for reproof, teaching and salvation.
So it seems that Bonhoeffer's assertion is correct, and the reason is a battle against unbelief. So are all sins the same? Yes. The answer must be yes. But the hold that a given sin has on a person may vary, as Bonhoeffer points out. Yet even still, the Gospel overcomes all sin and unbelief through the forgiveness of sins.