A Catechism is a manual of Christian doctrine drawn up in the form of questions and answers, especially one for religious instruction. The first such manual was compiled by the English scholar Alcuin in the 8th century. Emphasis on the use of a catechism, particularly its memorization by rote, has diminished in recent years.
A confession is a manual of Christian doctrine drawn up in the form of essays. Confessions are typically written in a chapter format and grouped according to a particular subject. there are a great number of proof texts which provide the Scriptural basis for each subject.
Creeds are authoritative summaries of the principal articles of faith of various churches or bodies of believers. Since doctrines are subject to elaboration and interpretation that cause differences of opinion detailed creeds become necessary to emphasize the differences between the tenets of schismatic branches. They also serve as formulations of belief when liturgical usage, as in the administration of baptism, requires a profession of faith.
The historical 95 theses that Martin Luther nailed to the door of the Church in Wittenburg. Each of these speak to Luther's desire for people to look deeper into what it means to be a Christian.