Christian discipleship and institutions: three types

We've been discussing the relation between community and institution in my ecclesiology class. In this week's class I tried to summarise the issues by explaining the way institutions can be more or less aligned with the teaching of Christ – here's a 15-minute audio snippet from the lecture:
Following this account of "institutional conversion", I suggested three different types of Christian discipleship in relation to institutions:

1. Conversion through participation: attempting to align an institution more closely with the teaching of the gospel. Generally this is possible where the founding purpose of an institution was derived from the gospel. Examples: hospitals, schools, law, welfare agencies (as explained in the audio snippet above) – in fact, most major Western social institutions.

2. Contradiction through participation: working within an institution in a way that reveals the contradiction between the gospel and the values of that institution. Generally this is necessary where the founding purpose of an institution directly contradicts the teaching of the gospel. Examples: a Christian working in a casino cannot seek to align that institution to the gospel, but can embody the teaching of Christ through a life that abstains completely from gambling and the glorification of luck. Such a life bears witness to the moral world of the gospel in contradiction to the moral world of the institution. I know of pacifist Christians who serve as military chaplains in the same spirit: they seek to serve their military institution faithfully in a way that nevertheless bears witness to the contradictory values of the gospel.

3. Contradiction through coercion: using social power to coerce an institution into altering its aims or practices; here the gospel is revealed as judgment on an institution and its goals. Examples: the use of parliamentary processes in the abolition of slavery in England; or current organisations like Not for Sale and Stop the Traffik, which use combined strategies of law, lobbying, education, and corporate support to effect social change. In such cases, Christians make use of some social institutions (law, media, etc) in an attempt to constrain, or even to dismantle completely, an institution that is believed to be the cause of unequivocal social harm.

OK, I know this schematic outline is far from perfect, and I know that actual institutions are more complicated, both in their goals and in their structures, than this outline suggests. But without some differentiated account of institutions and their relationship to the Christian community, I don't see how we can even begin to reflect responsibly on Christian vocation in our world. I've come to believe that sweeping theological dismissals of institutions are a menace to Christian discipleship.