What about a 'causa'-gerundive type phrase ("[what we are doing is] for the sake of defending the Church and Her people"..etc)? This phrase has a sense of purpose to me, I feel like I wouldn't use an infinitive for that.. "..Ecclesiae populique conservandae causa" or something along those lines if it could be said better
hm well I just realized this original thread was from about 8 years ago or so, guess I was a bit late in coming.. lol