Be sure to let me know when you find out who has the direct link to God so we'll know the answer to all moral problems. In the meantime, we'll keep making the decisions ourselves. Subjectively.
Funny you should mention that... I was just thinking about Scripture, and more specifically the Ten Commandments of the Old Testament (found in Exodus 20). Within a Theistic universe framework, these commandments make perfect sense.
1) No other gods. If God is truly God, and other so-called gods are not, then serving another so-called god will lead to moral error, which we know leads to conflict between humans, and ultimately leads to things like war, killing, and exploitation of the weak (all common in the religions/societies of the ancient middle east, and today). Also, importantly, whatever humans worship, they become more like.
2) No images/idols. Again, if God is truly God, then making an image from one's imagination and serving it is an insult to God, who has no material shape... it cheapens our understanding of who He is. Second, serving an image of our imagination would eventually lead one to also begin forming our own moral beliefs from our imaginations, which would bring us back to why the first commandment makes sense.
3) Don't make false oaths in His name/lie in His name. Contrary to popular belief, this commandment is not about using the name of God as a swear word (although that's not a good thing either). It is about representing who He is by not speaking falsely and attaching His character to it. Lying is morally wrong in general (with rare exceptions), being false or deceptive in His name is doubly wrong. Again, it misrepresents who God is and cheapens our understanding of Him. Again, whatever humans worship, they will become more like.
4) Keep the Sabbath. Up until this point, the main objective of the commandments was to regulate our relationship to God. This commandment has that aspect, but is also regulating our relationship to each other. Since God "rested" after the work of creation (meaning he was no longer creating), it is also right for humans to take a day off from work and devote it to their relationship to God, and also one another as they rested in their homes. Hard to argue against a day off from work, and using that time to build one's relationship to God and family is a much better thing than watching the games, taking in vacuous entertainment, etc.
5) Honor your parents. The focus is now squarely upon how individuals relate to one another, in the context of a right relationship with God. How a society treats it's elderly says a lot about it. In a context where everyone is following God, treating each other with value and respect, it would only be right for children to honor their parents while young by listening to them and being obedient to their wise counsel. And also when the child becomes an adult, and their parents lose their ability to provide for themselves, honoring them by caring for and providing for them is definitely a good thing. The only way this could be viewed in a bad light is if the parents themselves were not following God, and were abusive and mean to their families... this commandment (as many others do) assumes that the individuals involved were following God faithfully overall.
6) Do not murder. Obviously, the idea here is that in the context of the law, taking a life unjustly, with premeditation (it is clearly framed this way elsewhere), is wrong and should not be allowed in any kind of good society.
7) No adultery. To betray the one who is supposed to be your closest ally in life in this way is just plain wrong, assuming that both parties are living within the boundaries of a larger relation to God. And even if they were not, there were ways for both parties to end a marriage (it was admittedly more difficult for a woman, and the standard for dissolving a marriage was rightly very high), and to disrespect yourself, your spouse, the other person involved (as either a meaningless fling, a tool to punish your spouse, or a head start on a new relationship before dealing with the current one), and God by being unfaithful to your vows before Him and each other by adultery is extremely difficult to justify.
8) Do not steal. Duh. Again, in the context of the society that God established being followed, where the poor could always find food and shelter, and everyone had a way to regain sold property through jubilee years or extended family, stealing is really hard to justify.
9) False testimony. Lying under oath in order to bring punishment to an innocent party in legal proceedings. In the context of the society God established following God and His laws, it's just obvious that this would be wrong. If the party was guilty, but there was not enough evidence to convict, trusting that God would make things right eventually is perfectly reasonable.
10) Do not covet what is not yours. What we wrongly desire inside is the launching pad for every kind of wrong act. It's not wrong to desire to have the kind of relationship that your married friends have, but it IS wrong to desire to have that particular person as your own. Desiring a better home, or better farm animals, is not wrong, but to desire the very home or animals your neighbor has for your own is wrong. Not really that complicated. It betrays a lack of trust in God to provide what you need, and it also leads to all kinds of actions that would demean, abuse, or harm others.
All of this is placed in it's full context in the New Testament. Every single law given by God hangs on the framework of two overarching laws presented elsewhere in the Old Testament. 1) Love God above all, and 2) love your neighbor as yourself. It was clear that the teachers of Jesus' time understood this as well (Luke 10:25-28), and it is likely that was not a new development considering the weight that 1st century Hebrew teachers placed upon tradition.
Now, I will not pretend to understand every single law of the Old Testament, as quite often these laws were given as an explicit correction of the religious practices of ancient Egypt, and those of the people groups that Israel drove out of the land, and we really don't have detailed knowledge of all of those practices. But for those laws that I do understand, I find a clear moral framework for worshipping a God who is worthy of it, treating others with care and value, and taking care of the world that we live in. It is quite possible to find things to object to individually in the Law, even in those things we understand fully, but in the whole context of a faithful people following the God presented in the Bible, it really makes a lot of sense.
As I said before, the Scripture is unable to guide me in every singe possible scenario I face in this world, but it does give me a moral framework to work within, and more importantly, it helps me understand the character and nature of the God who has promised to dwell within the faithful believer, and guide them into all truth.
Still, there is a constant tension between knowing His guidance, and resisting my tendency to be self serving, lazy, or mean. Sometimes, I go days (or even longer), out of laziness, business, and doubt, where I am not meaningfully connected to His Spirit, and I'm not hearing Him. But when I slow down, push out the noise of our world, deny my own selfish tendencies, and just listen for Him and faithfully follow His guidance... I am constantly amazed, and reassured of my faith, as I see Him work in and through me.
Don't even think about following me, or any other Christian, though... we'll fail you. I'll misunderstand. I'll do something selfish or stupid. I'll go through long periods of time where I'm just not really connected to Him. But I can tell you, He's there. He's real. He's faithful to give us what He promises. Life. Love. Hope. Truth. Fellowship.
Look first at yourself. Your need. Your failings. Your desire for something, Someone, better. Then look at Jesus, as He is revealed in the New Testament. He will not disappoint. Ever.