A helpful excerpt from the Heidelberg Catechism
Q. 22 .What then must a Christian believe?
A. All that is promised us in the gospel, a summary of which is taught us in the articles of the Apostles' Creed, our universally acknowledged confession of faith.
The catechism goes on to list the promises of the movements of the Creed. It is very helpful. I would not formulate many things the same way the catechism does, but it is deeply edifying. I highly recommend a read through:
http://www.crcna.org/welcome/beliefs/confessions/heidelberg-catechism