I suppose there probably never be a concrete objective meaning to live, at least not one humans will discover or comprehend. People can create their own subjective interpretations of it.
Different life experiences and religious upbringing will dramatically affect how they perceive different things. A Muslim with a strict religious upbringing may view the purpose of life to be to serve Allah, while a athesis/agnostic with a poor childhood may see life as having no meaning and is nothing more than a series of chaotic random events.
I think so, I've never seen religion and science as being mutually exclusive ways of explaining the world and by extension life. Science acts as a tangible explanation to how (we currently understand) how the world works around us. Religion acts more as a guide on how to live our lives but usually can be interpreted in different ways and most religious stories act more as metaphors rather than historically accurate events. For example, the destruction of Sodom and Gammora may have never actually happened but it shows the consequences of living a meaningless existence that only chases pleasure.
I hope I didn't misunderstand the question.
Some people may find the meaning of their own life in their relations with others. Say a dad finds his purpose is to raise his sons to be better and more successful men than he was.
I don't think happiness is the ultimate goal in life. If it was then acquiring lots of short term happiness (hedonism) would be the most logical path to follow. of course, it's on a person-to-person basis but I think the ultimate goal of life is to find purpose. To be able to find some kind of reason to say you were born besides random chance, even if that purpose may not necessarily bring happiness.
Your purpose in life may be to sacrifice yourself for others so they may live or have a better life than you did. Maybe your purpose in life to live a humble life as a cog in the machine to ensure it keeps running and so on. These probably won't bring you much happiness but it will give you a reason why you're here.