Have you ever stopped to think about the implications of the phrase "who do you think you are"? We usually say this to someone who has overstepped their boundaries. Perhaps they have judged us in a way we'd rather them not judge us. Perhaps they have done something that makes us judge them. They've said something rude, they've taken something they have no right to, they've walked into a place they have no business being. Perhaps they've told us to do, or not do, something, or made a comment about someone we care about.
Whatever the reason we say "who do you think you are?", we imply that there is someone who can say or do these things. And of course, this implication is 100% correct. God.
Many object to God's right to command them, or punish them for breaking His commands, yet none of them can explain what actually gives them the right to this objection. See, if there is no God, there are no actual morals. There are things that might make certain people believe or behave in certain ways, but at the end of the day, morality is not a "thing". It is not a force, like gravity or friction. It's not a gas, like air. It's not a liquid, like water. It's not a solid, like us. You cannot observe "right" and "wrong". It exists, if indeed there is no God, only in the minds of equal individuals, constantly struggling to enforce their will upon others.
But what makes God's will dominant in all of this, first of all, is simply because His is the same voice that spoke everything into existence. God said "let there be light", and there was light, exactly as He commanded it, and exactly as He envisioned it. And the same with everything else. The only thing that makes man any different from the rest of creation is that God gave us the ability to disobey. If God says to the weather "thou shalt not storm", it will be calm, but if God says to a man "thou shalt not murder", we'll have 6,000 years of bloodshed.
But giving us the ability to disobey is not the same as giving us the right to. Thus, the second thing that makes God's opinion superior is that our delusion is temporary. See, when we keep each other in check, we fail. We might try to stop someone doing something bad, they do it anyway. We might try to punish evildoers, they'll do it again. They may even get away with it. No one held Jack the Ripper accountable, for example.
That is, except God. Jack the Ripper may have died in anonymity, but God always knew exactly who he is, what he did, and how to bring him to justice. Assuming Jack the Ripper did not repent, he was adequately judged for his misdeeds, and now awaits the resurrection to shame and everlasting contempt (Daniel 12:2).
Ultimately, God is the standard. He will judge us based on how well we conform to Him. Furthermore, He is not arbitrary. Scripture tells us He has, has always had, and will always have, the same nature, which means He will always have the same will. Unlike us, He does not change, never saying "this is wrong because I happen to feel that way right now", never learning new information that makes Him say "I used to think like that, but now...". Even in areas where it seems He has changed, it's actually a situational thing. His morals are almost like a computer: "If X then Y, else Z". Whether God says "thou shalt Y" or "thou shalt Z" depends entirely on the X.
You may think of it this way: We are also creators. We create different things for different purposes. We don't poo in teacups, we don't bathe in toilets, we don't drink tea from bathtubs. Furthermore, we are possessive. We have the right to pick our own locks, and we may commission a locksmith to do likewise, but woe betide the unauthorised lockpicker. And if I want to break my own mugs, who has the right to stop me? But do I not have the right to stop you from breaking my mugs? But the question is, why would I break my own stuff? Well, perhaps if I created it to break. We might make things like clay pigeons, or even a rage room. But another reason to break something we own is that it simply doesn't work the way we intended.
God has every right to rule His creation His way, and we are His creations. We can be grateful for this: He can make things for the sole purpose of destroying them. If God wants to grow a plant just so we can eat it, that's His right. If God wants to grow a plant and tell us not to eat it, He has every right to do so. What if we eat the plant anyway? The punishment He set, again, is His absolute right.
But we were not designed for the purpose of destruction. God tells us He has no pleasure in the death of the wicked (Ezekiel 18:32; 33:11), does not desire that any should perish (2 Peter 3:9), but wanting all men to be saved and come to the knowledge of the truth (1 Timothy 2:3-4). Furthermore, God tells us Hell was designed not for man, but for the devil and his angels (Matthew 25:41). God has the right to condemn us, but not the desire.
The problem is, however, God follows His own rules perfectly. The Bible even tells us He cannot deny Himself (2 Timothy 2:13). That means justice must be done, and there's no way around that. However, God makes salvation possible. To do this, He can't just forgive and forget as if we never did anything wrong. That's arbitrary and unjust, and frankly, it is worse to suffer an injustice than it is to suffer justice. So what's the answer?
The answer God gave is to become the perfect mediator between man and God: The man Jesus Christ (1 Timothy 2:5), in whom the fullness of the Godhead dwells bodily (Colossians 2:9). Being both God and man, Jesus is able to represent God to man, and man to God. During His life, Jesus never once sinned. He never did, said, or even thought anything wrong. Nevertheless, He died as a sinner. The Bible tells us "For He made Him who knew no sin to be sin for us, that we might become the righteousness of God in Him." (2 Corinthians 5:21).
The fancy term for this is "Penal Substitutionary Atonement", but in simple words, it just means we swap verdicts. We, being sinners, deserve death, yet God treats us as righteous and rewards us, because Jesus, being righteous, deserves to be exalted, yet He humbled Himself to death on a cross.
The sole condition to receiving this free gift is faith. Those who confess Jesus as Lord, and believe in their hearts God raised Him from the dead, will be saved. This begins a lifelong process of reformation, being taken from our state of constant rebellion against God, and brought to repentance. In the end, we die, and like all men, we receive judgement. But instead of the condemnation we deserve, we enter God's everlasting Kingdom, never to suffer or sin again. Thus, our options are to be broken and proud, only to be destroyed with the rest of the defective trash, or to be broken and fixed until we claim our rightful place in God's Kingdom.