Morality is about love being right and justice being right as in principles.  It denies they are mere opinions or in any way arbitrary.  Rules appear when you to guide people in the ways of love and justice.  Relativists talk about morality but they redefine it as opinion.  That is not morality at all.

If morality is arbitrary or relative then it is based on power. It is the product of power not of reason. But surely if morality is objectively true it is also based on power? Or more so! The answer is that it is based on power but as something has to be there is nothing too much wrong with that. Arbitrary morality is just plain evil.  It is guesswork and opinion posing as obligations.

Relativists usually are relativists because they think the notion of objective morality is about power and that is enough to make it a bad thing. The fact that objective morality is needed means the power objection does not refute it for anything else leads to worse power-mongering. Objective morality when thought out right warns us to be as liberal as possible without watering down moral principles.

The view that objective morality defends itself and needs no assistance accuses those who disagree that what you have really is objective morality of blindness and bigotry.

Morality is a necessary evil in the sense that it binds us and threatens us if we refuse to obey it. Morality is self-justifying even if all you can manage to show that is a process of elimination.
If morality is a necessary evil then its self-justification would be one too.

If we need justice and love then don't pretend that this is actually good.  It is necessary but not exactly good.  It is the best of a bad lot.  Religion thrives on using God as a totem of goodness to attract people with warm fuzzy feelings about "God's righteousness."  That is anything but moral.