Without objectivity, morality is subjective, and therefore, nonexistent.
We can state objectively that death isn't a very good thing because it ends your existence, (do note: in each case I am talking rational - it clearly would not include the delusional fundie types that think there is some godly benefit to be had from self extermination, those suffering from a pain beyond their ability to cope with etc), and survival is priority.
(If you really feel the need to question
why survival is so important to living organisms it can be simply stated that any organisms that
didn't think survival was important have all died and hence ended up extinct).
We can state objectively that humans have physical needs, mental needs, social needs.
We can state objectively that humans are a communal species, (along with most primates and some other animals).
We can state objectively that humans need other members of their community in order to ensure their own survival.
These things are all as
objective as it gets.
From these objective facts we can state objectively that an action detrimental to the needs of the community are wrong, (say, killing one of the group for example). Of course this does depend largely upon circumstance. As I'm sure you will agree, if your neighbour killed one person but in doing so saved 1,000 people you would consider it morally justified but only because it wasn't detrimental but indeed beneficial to the good of the group - a group you, as a communal species, are objectively a part of.
Various communities will differ in various ways regarding what is good for it but you will find that these are not objective matters but specific group matters. Theists are the prime example of this.. E.g:
A christian, (of which you are one today), would contend that 'homosexuality' is bad. There is however nothing objective in this, it is a personal opinion based upon personal needs and values. Indeed far from being detrimental to a group homosexuals can be very beneficial - there are various professions that you'll find are largely filled by homosexuals because they're better at it. Some might argue that a man sticking his willy up another mans bum is detrimental to the group but I don't see how, (unless perhaps they do it in public).
Once again: this is all as objective as it gets. It is in fact the theist that appeals to the subjective in order to persuade others to take on his own subjective personal ideals and opinions - that all work on the basis of some invisible god and his ever changing rules and regs.
Take for instance stoning naughty children or prostitutes to death. There's nothing objective about that and yet this god commanded it. When he commanded it you must contend and argue that it is objective because this god commanded it - and yet we all sit here knowing that it isn't. Nowadays of course, the same believers in this god and his "word" and those objective morals have done a complete 360 and now think it is objectively the opposite, (which it actually is - because of the reasons mentioned earlier).
So, out of interest, why is an objective moral law, (stoning kids/prostitutes and not suffering a witch to live - at the commands of a god), now objectively the complete opposite? Does your god change opinions much or have even theists had to catch up and recognise objective morality for what it really is? Of course that does not stop those theists from hanging on to those subjective morals that aren't actually objective, (homosexuality etc), by the very nature of it not being objective.
Snake