It has taken my entire life, but I have finally come to understand that we cannot judge people by only their words or actions. People can do all the "right" things but for all the "wrong" reasons. In order to fully understand where people are coming from, we need to know what is motivating them. And our Lord says there should actually be only one overriding motive in our lives: love. Specifically, Love of God and love of neighbor. Any other motivation - power, prestige, money, security, etc. - is of the devil. As St. Paul tells us, unless we love, nothing we do has any real meaning (I Corinthians 13).
This is why Our Lord warned us that people can think they doing God a service when they kill others. And sometimes we can "kill" others without even physically harming them.
That is basically the theme of an article in La Civiltà Cattolica entitled, "EVANGELICAL FUNDAMENTALISM AND CATHOLIC INTEGRALISM: A SURPRISING ECUMENISM" written by Antonio Spadaro and Marcelo Figueroa. This point of this article is the danger arising from an ideological movement of some Catholics and evangelical Protestants joining together to fight our evil culture, specifically against such evils as abortion and same sex marriage. This movement sees politics as the savior of the world: if we can just get the right people into public office and then get the right people on the Supreme Court, then our society can be saved from the evil, godless Left.