5. Sola ecclesia (through the church alone) - This newly recognized sola is needed to battle the extreme individualism and anti-church sentiment that is becoming more and more prevalent. I hear: "I believe in Jesus but I don't trust organized religion." "All the churches are full of judgmental hypocrites." "I don't have to go to church to be a Christian, I can just watch services on TV." Surely you have heard similar statements; they are very common these days. Let us examine the historical and present value of the Church for salvation and sanctification.(source)
[I've removed the body of his argument here. The conclusion of the section follows.]
A final warning is in order for this particular sola. There is a reason why sola scriptura comes before sola ecclesia. Church authority must always be secondary to the authority of God's Word. All traditions of doctrine, worship, and human authority in the church must be tested by the Canon. In the history of the Church, we have seen how human power tends to corrupt and change things. But Jesus Christ does not change (Hebrews 13:8, Rev 1:8) and His words will never pass away (Matthew 24:35). Humans (other than Jesus) can and do change, sometimes for the worse. Remember that the churches in the world are still made up of both sheep and goats, and there are some wolves in sheep's clothing at the highest levels.
Given the other sense that sola ecclesia already has, I don't think it's the best proposal, but it is an interesting one.