A quick response here on one point:
>>>"You will find the Westminster Confession and the London Baptist Confession uses only scripture. There isn't much to argue about."
Then again, what is the purpose. I know the idea of a summary, but there is not a meaning or interpretation or dogma/doctrine derived then what's the point, really?
I guess I'm not accepting the answer: it's only scripture. Scripture is short enough.
What do you mean by meaning or interpretation? If you mean can a Baptist and a Presbyterian look at the same text and interpret scripture differently then the answer is yes. Are there stark differences then in their catechisms? The answer is no. Unlike Catholic catechisms which totals into the 1,000s, there really are only a little more then 20 catechisms of the Protestant church. Charles Spurgeon had 82 but even he got tired. Protestant catechisms are rather clear and straight forward:
80.Q. What is the Lord's Supper? A. The Lord's Supper is an ordinance of the New Testament, instituted by Jesus Christ; wherein, by giving and receiving bread and wine, according to his appointment, his death is shown forth (1 Cor. 11:23-26), and the worthy receivers are, not after a corporeal and carnal manner, but by faith, made partakers of his body and blood, with all his benefits, to their spiritual nourishment, and growth in grace (1 Cor. 10:16).
There isn't much wiggle room and I doubt if you'll find a Protestant (even a liberal one) who would disagree with that interpretation. Compare this to the
Catholic Church catechism of the Eucharist which is literally pages. Here is just one line of the Eucharist many catechisms:
1324 The Eucharist is "the source and summit of the Christian life."136 "The other sacraments, and indeed all ecclesiastical ministries and works of the apostolate, are bound up with the Eucharist and are oriented toward it. For in the blessed Eucharist is contained the whole spiritual good of the Church, namely Christ himself, our Pasch."137 136 LG 11.
137 PO 5.
What in the heck does this mean???? The purpose of catechisms is to train people in the faith. See if you can recite all the Eucharist catechisms by heart. See if you can find any scripture that supports this statement. This catechism sure sounds pretty but there is no basis and no references, not to mention it's totally confusing. Do you know what "LG 11" or "PO 5" refers to?
Protestants like to keep things simple. And, unlike Catholic catechisms, one can easily look up the reference on the Protestant catechism to see if they're being sold snake oil. Sure, Protestants can argue whether we should serve only wine or whether grape juice is permissible, but it doesn't change the purpose of the Lord's Supper nor the text which supports the meaning of it. This is not true of the Catholic catechism for which there is no context and vague references. I remember trying to look up the references of several Catholic catechisms only to give up.
Please keep in mind that most Protestants do not understand their catechism just like most Catholics don't understand theirs. Therein often lies the confusion.