Catholics tend to be slightly more forgiving than protestants, and attitudes among Christians on who is and who is not a good Christian vary mostly according to political ideology
YouGov's latest research shows that attitudes to who is and is not a good Christian vary widely according to the topic, but less according to the denomination. Most American Christians think you can be a good Christian and drink while married to a non-Christian, but few think that you can be a good Christian and support legal abortion.
In general, however, Catholics tend to be more forgiving than protestants. 67% of Catholics say you can be a good Christian and be married to a non-Christian, compared to 56% of protestants. 37% of Catholics also say you can be a good Christian and also be in a same-sex relationship, compared to 27% of protestants. Protesants (29%) are more tolerant of supporting legal abortion than Catholics (20%), however.
Political ideology matters far more to differences between Christians than denomination. For example, Americans generally say that you cannot (41%) be a good Christian if you support legal abortion, but most liberal Christians (52%) disagree and say that you can be a good Christian while being pro-choice. Moderate Christians (42%) and most conservative Christians (62%) tend to disagree.