Which doctrines from the Reformation are most needed today?

Gary Powers explains in this video that many modern churches today fail to believe that Scripture is sufficient for all matters of life. But, once the church strays away from the foundation of Scripture, all aspects of church life and doctrine are negatively affected. 

Without Scripture to act as an unchanging standard, the church has no direction and will undoubtedly stray from Scripture. Acknowledging that Scripture is sufficient is the first important step towards reformation.

Psalm 102:25-27 (NKJV) – “Of old You laid the foundation of the earth, and the heavens are the work of Your hands. They will perish, but You will endure; Yes, they will all grow old like a garment; Like a cloak You will change them, And they will be changed. But You are the same, And Your years will have no end.”

I think the church understands the doctrines that came out of the Reformation that are most significant for us today, I think, or have helped us the most today. I think the church understands salvation by grace alone and faith alone. I'm not so sure that we fully understand scripture alone. I think we understand the infallibility of the word and we understand that scripture is divinely inspired by God, but I don't think many in the church today believe in the sufficiency of scripture. That God has given us everything that we need for life and godliness.