So. It would be impossible to answer this question definitively without writing a series of books on the topic, for a few reasons:

• Greek and Roman religion are actually very different, and not at all interchangeable. We often think of Roman religion as being Greek religion under a different name, but it's far more complicated than that. Roman religion was inherently very syncretic (i.e. made up of lots of assimilated religions and influences) due to the nature of the expansion of the Roman empire, and was also heavily influenced by Etruscan beliefs. This essentially means that Roman religion was a melting pot of different moral codes, cultural norms and spiritual beliefs. Greek religion was as well, but to a less overt extent.
• Greek and Roman religion, if we're talking the paganism model, spans a period of hundreds and hundreds of years. Greek religion in 400BC, for example, was very, very different to the religion of that same region in 100AD, even if the names of the gods, the rituals and the core beliefs were constant. Belief evolves based on cultural behaviour and context; the religion of a country at war, for example, will often become more fervent.
• Greek and Roman society, again, were very different. Greek ideas of morality were not the same as Roman ideas. To use a religious example, it helps to look at the representation of the respective gods associated with war: Ares in Greek religion, and Mars in Roman religion. In Greek religion, Ares was often depicted as something of a comical figure, or at the very least as a figure whose war-mongering personality was often detrimental to military success. In short, he desired war, but wasn't really capable of managing it. For that, the Greeks invoked Athena. In comparison, Mars (often cited as the 'equivalent' of Ares) was a well respected and often invoked god in Rome. Many of the myths associated with him show the glory of war as an entity, as a vehicle for empire. He was almost a paternal figure to Roman culture, which linked him with the very genesis of their religion. The difference in the reception of these gods does help to illustrate the different values of Greek and Roman society. Rome was concerned with empire and imperialism, shown by their veneration of war as an ideology. Greece, on the other hand, often prioritised strategy, logic and military strategy, shown by their preference of Athena. That's something of a generalisation, but it indicates that the societies were not interchangeable.
• Morality isn't singular in any religion or society. Catholic morality in England is very different to Evangelical morality in Texas, to use a contemporaneous example. Similarly, ideas of what were good and bad were not the same in Athens and Lesbos, even contemporaneously; different religious cults were popular across varying regions, which carried with them nuanced moral codes. The best example of this would probably be the difference between the cults of Dionysus, whose followers would be expected to engage in ritual madness, eroticism and revelry at allotted times and places, and of Athena, whose cult prioritised virginity and level-headedness. They weren't two separate religions, but by concentrating on different aspects of that same core ideology, an individual could essentially either adjust their beliefs to suit their moral code, or vice versa.

However, some ideas that are fairly consistently incompatible with our current idea of good and evil is the fact that the idea of sin is, largely, not extant in Classical religions. The notion that one must live a pure, ideal life in order to pass onto Heaven in the afterlife is a purely Christian notion. Greek religion in particular did not view the afterlife purely in terms of good and bad. Hades, for example (the place rather than the god) is often characterised today as being equivalent to Hell; a place of torture for sinners. That's simply not accurate. Hades was just where the dead went. You could be a man who was universally considered unpleasant, or a woman who was generally loved by all around her, and either way you would likely end up in Hades. There was a nasty alternative for those who committed really grievous crimes such as matricide or hubris, which was Tartarus, but it wasn't just for 'bad people'; it was really for those who had escaped terrible punishment in life which needed to be addressed. The other alternative was Elysium, which was a sort of utopian place, but you generally had to be a hero, a demigod or have some sort of connection to the gods to be admitted there. Again, it wasn't strictly about morality; you could be a fantastic person who gave all your money to charity, and you'd still end up in Hades with the man who stole charitable donations. Essentially, Greek religion did not differentiate between good and evil as determining the merits of the soul and its suitability for any kind of eternal life.

Another core idea to remember is the idea of justice as balance. This is particularly evident in the Aeschylus trilogy, the Oresteia; Iphigenia is sacrificed by her father, Agamemnon, who is then killed by his wife, Clytemnestra, who is then murdered by her son, Orestes. Of these murders, the killing of Agamemnon by Clytemnestra is by far the one judged most severely, because the life of a man (the head of the household) is weighted by society as being worth more than that of a woman. This creates a blood debt and an imbalance in the household, which is only rebalanced when Athena intervenes. Of course, the Oresteia is a dramatic text and is not representative of real life at the time, but it gives an example of the idea. 'An eye for an eye' was more of an acceptable viewpoint than it is today. The second crime would be considered against the weight of the first, rather than as a separate act in and of itself. This did become less the case as Greece developed into a political democracy, but there were elements of it to be found across the mythological landscape.

Finally, it was very important to keep in mind that what was true and acceptable for the gods did not necessarily apply to you. Gods could act in ways that mortals could not; Zeus, for example, could commit frequent adultery and rape, whereas adultery was a crime in law. One of the most grievous errors you could make was hubris, i.e. assuming yourself to be on the same level as a god. Again, this is visible in myth with the story of Icarus.

I hope some of that was useful! If you have more specific questions (i.e. about Greek vs Roman religion) then feel free to ask; I've written dissertations on both Greek and Roman morality, so can answer more succinctly. I can provide a list of sources as well with a more specific request; the list would just be far too long to attempt to cover Greek and Roman religious morality accurately.