The very first time I ever heard an apologist speak, It was a short video taken during a Q&A where Ravi Zacharias was the keynote speaker. Here it is.
The question posed is “Why are you so afraid of subjective moral reasoning?”
Dr. Zacharias does give a thoughtful response, but there are a couple of ideas that, I assume because of time restrictions and the long line of questioners, he didn’t take the time to explore or expand upon.
To quote the famous atheist Fedor Dostoevsky, “Without God, all things are permitted.” If the origins of supreme morality do not transcend humans, subjective morality is as good as any, but if God delivered us guidance on morality and showed us the way, then we have something far, far better. We would be fools not to take it.
Why is subjective morality so scary? Because there really are people and forces out there that would sow nothing but seeds of destruction and death if left to it. If morality is left simply to the individual or popular opinion, we have no solid ground on which to stand against those that would do evil...we wouldn’t necessarily even know what “evil” is ("The Parable of the Madman" by Friedrich Nietzsche). Thankfully because of God’s gift to us in scripture and the example set by Jesus, we don’t need to invent our own morality. We don’t have to fight about whose morality is better or worse between us. Further, we have grounds on which to argue against someone who wishes to do harm to others based on their own subjective morality. There is a supreme ethic and definition for morality available to us handed down by the same God that created us and loves us beyond all limits.
"Owe no one anything, except to love each other, for the one who loves another has fulfilled the law. For the commandments, “You shall not commit adultery, You shall not murder, You shall not steal, You shall not covet,” and any other commandment, are summed up in this word: “You shall love your neighbor as yourself.” Love does no wrong to a neighbor; therefore love is the fulfilling of the law."