The Sally Army
The Trussell Trust
The ending of apartheid - Archbishop Tutu etc.
Tear Fund
Christian Aid
CAFOD
Etc.
Etc.
Every time I get annoyed by some nonsense posted on Facebook by some fundy nutter, and seriously consider abandoning Christianity and becoming a humanist, the member of this forum who started the other thread that this is a reply to comes out with some outrageous, one-sided slur against Christianity, and reminds me how bitter and negative I found myself becoming during my year out back in 1992-3, before I came back to a much more liberal version of the faith, which makes me decide not to throw it over just yet - so keep up the good work for the gospel, RJG! 
There are, of course, many charitable organisations established by christians with a christian ethos - you've indicated a few. But for every one you can match to other organisations that are acting in a similar charitable field (e.g. Homeless, emergency/developmental aid, etc etc) that are entirely secular in terms of formal designation and organisational ethos. And of course many of those organisations were set up by people who aren't religious and include non religious people as volunteers/donors etc etc.
So there really isn't any evidence that there are proportionately more christian charities than you'd expect given the proportion of christians in the UK. Nor of course is there evidence that christians are more likely to be volunteering more than non christians, nor giving more to charity than non christians (once you strip out donation to the church that active christian donors gain a direct benefit from in terms of attending worship).
However there is one difference - christians seem to require that charities are badged as christian, which doesn't happen in the secular world where most charities are named on the basis of the work they do, not the attributes/motivation of the people involved/setting up the charity. Why is this - well it seems to me that christians feel the need to be seen to be doing good work, while others have less need to seen being charitable, rather the fruits of that work are sufficient. You see this embedded in christian worship where the collection plate is clearly public (and of course there is no need for this).
So it seems to be that there is a mentality within christian tradition that needs to ensure that individual are seen to be doing good (rather than just doing good per se) and that they need very publicly to ensure that everyone knows that it is their christian faith that motivates them.