I've been pondering that case in Brazil where the RC church has excommunicated a nine-year old girl, her family and doctors, for having an abortion, yet has not excommunicated the person who did the evil deed itself. I think this is a good example of idolatry, and I want to unpack why as it may help to explain what I mean by idolatry (and also, for atheists, what I mean when I say that God is not a member of a set - an explanation which, whilst technically correct, ends up misleading, so I might abandon it.)
In Scriptural terms, we are called to love God with all our mind, soul, heart and strength - in other words, we must put God above all other things, we are not allowed to compromise with God.
This means that nothing else can be given the authority or perfection which belongs to God alone - not Scripture, not religious custom, not ethical principle. Nothing which can be described in human language is beyond being relativised by the fundamental command that we are to have no other gods but the one God. Furthermore we are to know this God, and the nature of this God, in order to carry out his will faithfully (that's what Scripture is about).
Using slightly more philosophical language, the teaching is that God is the only Absolute - and nothing else is allowed to become an absolute, for if it does, it usurps the place of God and becomes an idol.
In this instance, the principle of 'no abortion ever' has been made into an Absolute, and the suffering which will ensue on the child, the child's family, the doctors involved, and any future situations where a child dies from being prevented from having an abortion - this suffering is the consequence of idolatry. The teaching has been made into a rigid rule that is required to apply in any and all circumstances, no matter what the specifics of the situation. Morality and judgement become a technique rather than something involving the application of human feeling - and the absence of human feeling is one of the key signs that idolatry is present, for it is only human feeling, empathy and compassion, that can lead us rightly to God; it is these things which allow us to know what his 'way' actually is.
Note that calling this idolatry does NOT mean that the abortion is morally right in any 'pure' sense. What the idolatry in this case involves is an abandonment of the messiness of human life, the recognition that, in our fallen world, there are no morally pure, morally righteous alternatives. There are only choices between evils. Idolatry means that, in order to avoid one evil, a different evil is committed - and the idolatry blinds the idol-worshipper to the nature of that different evil.
In this case the lesser evil is the abortion - calling it a lesser evil acknowledges that it is still an evil - and the choice to never share in that evil has consequences that are a greater evil.
This is the sort of situation that I think Jesus had in mind with the story of the Good Samaritan. People are following religious precepts - they think that they are doing the right thing - yet their hearts have been hardened against compassion, and so they fail to do the Father's will. Consequently, those who have chosen this idolatrous path are liable to damnation for it.
6 Come, let us bow down in worship, let us kneel before the LORD our Maker;
7 for he is our God and we are the people of his pasture, the flock under his care. Today, if you hear his voice,
8 do not harden your hearts as you did at Meribah, as you did that day at Massah in the desert,
9 where your fathers tested and tried me, though they had seen what I did.
10 For forty years I was angry with that generation; I said, "They are a people whose hearts go astray, and they have not known my ways."
11 So I declared on oath in my anger, "They shall never enter my rest."
(from Psalm 95)