Reliable catechisms are of tremendous value to all believers, as well as to those concerned to learn the true nature of Christianity.  As Matthew Henry said, “Brief summaries of Christian doctrine are of great use to young beginners.  The principles of the oracles of God brought into a little compass in creeds and catechisms have, like the beams of the sun contracted in a burning glass, conveyed divine light and heat with a wonderful power.”  Richard Baxter said, “It is not the reading of many books which is necessary to make one wise, but the well-reading of a few, could they be sure to be the best.”    
See also the Catechisms on the Thomas Charles page.