I think it is valuable to understand what Protestants believe as far as the Church goes. First, they acknowledge that the Church was the steward of developing the New Testament Canon. But that was long before the Church became corrupt throughout the Middle Ages and beyond. In essence, Luther and others saved Christianity from the human depravity and error that had seeped in. Protestantism is the righteous continuation of the Church, not a splinter or unrelated offshoot.
They believe that Scripture is a gift of revelation from the Holy Spirit (not the Church). Any argument that suggests that the Catholic Church gave us Scripture is faulty, to say the least. On these points, I would agree.
Finally, they believe that Scripture alone in the ultimate authority because it is God’s own word. As Catholics, we would respectfully disagree, here. We see God’s revelation as presented through Scripture, Tradition and the teaching body of the Church, the Magisterium.
Some Protestants are quick to point out the matters of human frailty that existed just prior to the reformation…the greed, lust for power, and failure to effectively minister to God’s people led to the reformation. I am convinced that the times we feel that (because of our sinfulness) God is very far away, he is right next to us. The Church is what she is not because of men but because of the love and mercy of God.
Walk and speak humbly. Protestants can be very holy people worthy of God’s love. Though you may disagree on some points, resist the temptation to be better. Kind of like “My dad can beat your Dad up!” Rather, be open to what is being said. It’s just possible that God is using that Protestant to teach you something…