I agree that the virtues are admirable traits. They are a blessing to all that practice them, regenerate or not.
But the question was: what is the difference between the virtuous Catholic and the virtuous Muslim? Do you suggest that they are headed in the same direction? Are both working to gain the same end, much like Mother Teresa suggested when she said she was working to make Muslims better Muslims, Hindus better Hindus...?
I get where you are going and agree - it is through Christ we are saved, not practicing the virtues (though the virtues should be the gradually increasing visible fruit of a life of faith dedicated to Him). The difference between the virtuous Catholic and the virtuous Muslim is the root: faith in Christ-crucified and resurrected and knowing salvation is through Him alone. We must be cautious to ensure our striving for holiness is out of adoration for Him for Who He is as revealed in His Word and not to become subject to the Law once again. The virtues must spring forth from a heart crucified to Christ, in that for love of Him we choose to crucify the desires of the flesh which do not honor His Way and not seek to perform the virtues for the virtues themselves.
May He grant you a day richly blessed in His grace and His love in a way which all around you can see!
Catholics have the Sacraments of the Church. Moslems do not.
‘Unless you eat my body and drink my blood you cannot enter the Kingdom of Heaven.’