Look up the definition of morality and you will learn it is not religious centric, and has little to do with religion beliefs.
That that would depend upon the definition and nature of “good” or goods. Morality is essentially tied to goods, in particular to end goods. For most humans the highest end good is life itself, which is why anything that takes away or harms a life is considered morally wrong. It is possible to prioritize goods such that most people would agree on the ordering and that agreement would constitute the objectivity of morality.
Even so, the agreement of humans is not sufficient to decide whether they are correct on those end goods. Morality depends upon reality - the real state of those goods relative to humans. What would be the point if most humans valued something that turned out to make everyone miserable once it was attained? That is why Aristotle said the end which is generally agreed upon by humans to be the “good” is happiness (eudaemonia in Greek); not mere frivolous laughter or momentary joy, but enduring happiness resulting from a life well and fully lived.
This is where your comment that morality has nothing to do with God or religion becomes a little odd. If God exists and eternal life with God is possible then as a true end moral good, that level of existence simply dwarfs 60-90 years of the biological form of life we have on earth.
If true, then a “moral” person who lives his life ignoring or denying that God exists and lives a life that puts his eternal existence into jeopardy, then, it seems, that they could deprive themselves of a far greater and more substantial end good than the goods they have decided upon for themselves.
So, morality might be relative in the sense that individuals might differ regarding what they consider to be the end goods, BUT it is objective in terms of what those goods really are. Religion is crucial in this regard because whether any particular individual accepts it or not, what is true is what is. If you have the opportunity to obtain a truly wonderful end good - eternal life with God such that life will be eternally and absolutely filled with all that could possibly make it complete - then a whole new dimension is added to morality since the “stakes” are quite different than were presumed by a denial of God.
What makes morality objective is the reality of the goods involved, not whether humans agree on them or not.
If God does not exist morality is actually quite a meaningless illusion. If God exists there is an infinitely new and fuller sense in which things can be moral. Your claim that morality has little or nothing to do with religion is simply false.
Think about this. If you claim murder is wrong because it deprives people of their lives, then if human lives are potentially eternal and infinite, and by sinning or inducing others to sin you deprive them of their eternal life with God then the harm of merely killing them physically is dwarfed by the harm of killing them eternally. Which takes away an objectively greater good? Of course it isn’t quite that simple in most cases because, as moral agents, human beings are reponsible for their own choices.
All this does show that blithely denying that religion is moral might be one of the worst logical and moral errors anyone could make.