If you're going to try to add up the accomplishments for "Good" accomplished by "Christians" you will first need to come up with a way to determine what a "Christian" is and also you will need to define what "Good" is since as you well know, "Good" is something the United States is having a really hard time deciding on, whether it be for killing unborn children or exactly what we should indoctrinate young children who made it through the gauntlet with.
Christianity is not designed to be a powerful organization for creating heaven on earth by following a set of rules or enforcing right conduct or morals. Efforts to instrumentalize Christianity in this way have had dubious outcomes, the Catholic church and it's long history being a major example.
When you go into a human organization whether it is a church or an office building you're going to get a random mashup of people that for some reason or another happen to participate in that scenario, whether to pick up a pay check, or to be involved in a community, or to feel a bit less guilty, or actually to learn to be like Jesus.
Finding glaring examples of "Christians" being evil says nothing about the merits of following Jesus, failure is a fact in human endeavor. In much of church history, a lot has been said about what you need to -believe- in order to be considered a Christian. This is not a biblical concept as Christ himself actually asks people to practice specific things, and do specific things. Struggling with your own consciousness to actually love guys like Horza when he's flaming like a maniac is a big part of Christianity, showing up to sit in a chair on Sundays and smiling at people and projecting a positive affect for a couple hours is totally inconsequential. Jesus is concerned with matters of the heart and not really anything else.
Walking around with an intellectual acceptance of the teachings of the Bible while sneering at the grimey people taking advantage of some public space to pile trash and tents up is probably the worst place a human spirit can be. By worst I mean least prepared to actually become Christ like and by that I mean, getting aligned with the sole source of creativity, love, passion, joy, creation and whatever other positive things that exist.
For anyone interested in digging through hard mode, sound but challenging Christian philosophy I would point you towards George Macdonald maybe "Unspoken Sermons" for straight up lecturing or "Thomas Wingfold, Curate" to see a fictional example of someone elses journey (A minister in the church of england) to becoming an actual Christian. He's from about 1870's and everything in england at that time is basically the same as present day USA it's pretty startling.
For easier slightly more modern writing that is more technical and better for internet debates and generally the way we speak in present day, G.K. Chesterton's "Heretics" and "Orthodoxy" are a lot easier to digest but significantly less deep, being more in line with the kinda fighting we usually do about what is right and what is wrong which is generally kinda surface level.
https://www.gutenberg.org/ebooks/author/80
Both of these guys are public domain and written and audio versions of their works are available for free from gutenberg, just by putting them in a podcast, or by going to libravox where public domain audio recordings are compiled.
And reading George MacDonald with no personal context or history may be a bit like picking up a calculus book when you're struggling with times tables. I just wanted to point towards some real stuff for anyone wondering, not joel oldstein trash.