1. They think contraception (which all Christians before 1930 condemned as grave sin) is fine and dandy. (Note: Natural Family Planning, or NFP is essentially different from artificial contraception, and is fully supported by the Church, as I have written about several times).
2. They favor radical secularist / unisex feminism and women priests.
3. They think Jesus (and inspired Scripture) could be in error, and teach theological error.
4. They favor divorce, or at least a very loose application of annulments.
5. They deny the Real Presence.
6. They favor situational and relativist ethics (especially in sexual matters).
7. They habitually deny or disobey Church and papal authority and infallibility; pick and choose what they want to believe (Protestantized “cafeteria Catholicism”) and apply an erroneous, anti-traditional view of conscience.
8. They undermine and decry liturgical tradition.
9. They make the first eleven chapters of Genesis completely metaphorical, which subverts the doctrines of monogenism and original sin.
10. They underemphasize or downplay Catholic distinctive doctrines, and either adopt indifferentism, or something close to it, including the denial of “no salvation outside the Church.”
11. They deny the in partu virginity of Mary (physical virginity during the birth of Jesus), and sometimes perpetual virginity itself.
12. Some are even anti-supernaturalists; deny the devil’s existence (McBrien), various miracles (even those of Jesus), etc.
But if a person resists being corrected over and over in matters such as these (where Church teaching is clear), then we are dealing with intransigent modernism and a rebellious, disobedient spirit as to Church teaching. Sometimes we can only pray and leave it in God’s hands.
I don’t claim that my list is exhaustive. But it’s a handy guide to identify a liberal / modernist / dissident / heterodox / cafeteria Catholic.
For more along these lines, see my Liberal Theology & Modernism web page.
For further related comments and discussion, see the Facebook cross-posting.
(originally 1999, revised and expanded on 7-31-18)