Strange but true: The definition of a Practical Catholic, is a man who holds to the Seven Precepts of the Church, which are:
I. To attend Mass on Sundays and Holy Days of Obligation, and resting from servile works.
II. To observe the days of abstinence and fasting.
III. To confess our sins to a priest, at least once a year.
IV. To receive Our Lord Jesus Christ in the Holy Eucharist at least once a year during Easter Season.
V. To contribute to the support of the Church.
VI. To obey the laws of the Church concerning Matrimony.
VII. To participate in the Church's mission of Evangelization of Souls.(Missionary Spirit of the Church)
VI is incompatible with gay marriage. I've seen some say elsewhere that Pope Francis is more welcoming to gays, due to his statement about a priest who is actively trying to be celibate and who Pope Francis entrusted with high office: ""Who am I to judge them if they're seeking the Lord in good faith?". I suggest that those acting against the laws of the Church concerning Matrimony, whether gay or straight, is not seeking the Lord in good faith.
But notice what is missing. Belief in God is not required to be Catholic. Though I have NO idea why an atheist would do these seven items without belief in God- any of them.