Uh, there's also the Short Catechism, which does not come across to me as Sophist; if you go more deeply into Luther's Catechism, he buttresses every statement of his by Scripture, showing that the Creed is a statement based on Scripture.
What’s the purpose of a creed? If Scripture is the inspired word of God, then a creed either adds to it, takes away from it, or is redundant.
Creeds came about because councils and bureaucracies found them convenient to bind their particular organizations together. They are the fuel of religious division. http://www.bible.ca/r-creeds=fuel-division.htm
The creeds that have been adopted by various denominations simply violate Sola Scriptura and are nothing like the ancient declarations of faith they claim to follow: http://www.bible.ca/sola-scriptura-tradition-5-types-4-creeds.htm
Both Luther and Calvin violated the principle. http://www.bible.ca/sola-scriptura-anti-refuted-luther-calvin-creeds.htm