well yes i partly with you in regards to following ethics. But the other point i'd like to make is the selfishness of simply following ethics.

Living your life simply on the basis on "being a good person and not harming others" not only by virtue is deeply flawed, but also has a selfish undertone to it. e.g " I wouldn't steal from a person because i wouldn't like it if someone stole from me" or to give to charity, because if i were poor i would expect people to help me and treat me with kindness. Because in this world there are two types of good (one which you mentioned which i agree on):

First is "ethical good" (the golden rule: do to others what you do to yourself). So that can include: "im good to my neighbour, i dont cheat, im honest in my business, i don't steal, i do not cause any harm to people" these are good ethics.

the second type of good is "Religious Good" (i'll use Islam as an example) for a Muslim to be religiously good, he must pray 5 times a day, fast ramadan, do the pilgrimage to Mecca and believing in one God.

In every society you will find one group who will simply follow ethical goods (being good to your neighbour and so on not harming others, not stealing) but does not follow the religious good. (people who have no religion). And on the other extreme (some muslims are at fault in this i have to admit) you will find muslims who will act on their religious good which is praying 5 times, fasting ramadan and so on. However but turns out he is immoral and ethically bad. E.g. He cheats in business, he is dishonest, he steals, even the recent shooting in Toulouse France, if the man turns out he is a muslim and killed those jewish children that would be extremely unethical (despite the fact he may pray and so on). It is an extreme example but i hope you understand my point i'm trying to make

Thus living your life simply on the basis on "being a good person and not harming others" not only by virtue is deeply flawed, but also has a selfish undertone to it. e.g " I wouldn't steal from a person because i wouldn't like it if someone stole from me" or to give to charity, because if i were poor i would expect people to help me and treat me with kindness. Just like if a muslim would only follow the golden rule would be deeply flawed, as he MUST apply both principles (religious and ethical good) in order to be a universally good person speaking.

By virtue, if a muslim would apply the golden rule to the 5 a day prayer, "I would pray because he wouldn't like it if someone else prayed?!" it does not make sense. Praying is something you do for god and god alone hence the religious good differing greatly from ethical good in addition to being unselfish as opposed to ethical good.

With regards to your point on the burden of sin, you believe it does not exist. So if a man would commit a "sin" or commit an act that would go against the moral ethics, because sin does not exist by virtue they are immune to after-life punishment so they will only be accounted for their actions only in this life while they are alive. (e.g going to prison for drink driving, being fined for consensual sex of 2 or more people in public). With regards to alcohol we can acknowledge it is bad for you health wise and has an even higher risk when consumed while driving. Assuming that you drink yourself and that you are a responsible drinker, you will think to yourself "hey alcohol may be bad for your health, at least i don't get pissed everyday and beat my wife when i get home" or "at least i get pissed out of my head but I go drive a car".

The main point i am trying to make is that in essence if you follow your own sense of good or the ethical sense of good. if you define what is good for yourself, Than there can be no limit to how bad you be (by virtue), because in this world you will always find someone that is worse than you. And surely someone must draw the ultimate line of morality for human being to follow instead of human beings clashing with each other on what is good, when they themselves are not perfect.

So in conclusion correct of im wrong but no man has proven to demonstrate a level of morality and ethics that would suit every single human being on this planet as of today. Therefore my logicis to use people in the past as examples to follow in how they lived their lives until their deaths. Surely you would follow the advice of a person who not only was leading by good example but learnt from their mistakes as they got on with their lives until their death beds. Maybe the teachings of jesus, Muhammad (pbuh), Moses, Noah all the prophets may be the best example to follow in terms of the ethical goods they have commited in their lifetime (ignoring their religious good), instead of following an ongoing moral code to which you are not sure how it will be changed in the future, because you, me and every other living man on this earth will never find the ultimate ethical code due to our weaknesses and selfish desires.