In the USA they say math - "do the math"
But in Australia we say maths - "do the maths"

In the USA they say ways - "we've got a long ways to go"
But in Australia we say way - "we've got a long way to go"

In the USA they say Legos - "the children are playing with Legos"
But in Australia we say Lego - "the children are playing with Lego"

These are arbitrary social conventions which lead to arbitrary cultural differences.

We don't argue over them. We laugh about them. Who am I to impose my Australian way of speaking on an American?

But when it comes to ethical differences - euthanasia, embryos and the environment (I picked issues starting with E) - we do argue. We don't laugh about them. We do try to impose our views on the other side.

So when it comes to ethics - we can't say that they are social conventions.

But how can we determine who is right and who is wrong?

We can appeal to majority opinion - but does this mean minority voices are automatically wrong? We can appeal to what works best - but for who? We can appeal to God - but which God are we talking about?

If we are the starting point, we will have no reference point. But if we believe Jesus when he says that he is the starting point, then we do have a reference point.

This is why Jesus calls himself the Way. Or is it Ways?

John 14:6