Social Justice Is Not A Gospel Issue
Christians who say "social justice" is a "gospel issue" are often just engaging in a Christianized version of "stolen valor". They're wrapping their own political and social sensibilities in the majesty and wonder of Jesus at the cross. They're trying to make the cheap virtue of holding fashionable opinions carry the same moral weight as the costly virtue of actual self-sacrifice. They're playing word games with the gospel as a way to pat themselves on the back.
Just sayin.