if they can be moral without faith, that’s better than being immoral without faith
but it is harder, I think, to be moral without faith. faith in the source, the giver of both your life and those morals for your life.....helps provide you light/wisdom, also the strength, even courage...to know what the right choices are and then to actually do, pursue, take those choices. sometimes, at least, doing the right thing (even when you recognize what it is) can be very difficult. Faith can help, imho.
Here is a great 5 minute animated video “The Moral Argument” I have found useful in Catechism that addresses the God vs. morality issue. Worth a look IMO.
https://www.youtube.com/watch?v=OxiAikEk2vU
Cheers!
I would posit that the acceptance of morals, or the human attempt to be moral is a proof of the existence of God.
Its not harder , it is impossible.