God told me not to commit adultery, so it's wrong regardless of any other consideration. God told me not to eat pigs, but that's "ceremonial" as one of us puts it, and doesn't need to be obeyed. God told us to stone witches to death whenever we find them, but, so I'm told, that means that while witches are, indeed evil, as per the stoning instructions, God's intructions as to what to do about it are recinded.
Forgive me if I am unable to process this sensibly. I am still without a guideline that allows me to determine how to obey God's law.
Given that available manual for moral instruction from God, my heart does not instinctively know how to avoid offending God, contrary to the implied suggestion from several sources that this is so. This notion might make one feel warm and fuzzy, while putting in well-dressed, clean, and contemplative seat time in a pew, but it cuts no cheese when you have an actual, grimy, intractable use-case in front of you, and are trying to decide what you should do to be moral.
I am still without a guideline that allows me to determine how to obey God's law.
That is exactly the point! You cannot obey God's law. Nobody can. Nobody really even wants to. We have all sinned and come short of the glory of God. Nobody can please God except by faith. (If you want Scripture references for these, let me know.)
If anybody could be "good enough" to get to heaven, then Christ died for nothing.
It is all about love. When we love God with all our heart and mind and soul and strength and understanding - and love our neighbors as ourselves, we are free.
I strongly suggest reading - casually, not studying - the Sermon on the Mount (Matthew 5-7) and then the gospel of John. It is all about love and speaks directly to the heart.