You must use JSP, JSTL - is just set of custom tags and can not be used separately. As well as Expression Language. If you are not using any MVC frameworks, then you need to do some of their work by yourself. Please take a look (if you haven't yet) at following design patterns:
Front Controller
, Command
for simple application
Front Controller
, View Helper
for more complex application
UPD:
To resolve issue with EL, please try to correct JSTL uri in your JSP to:
<%@ taglib uri='http://java.sun.com/jsp/jstl/core' prefix='c'%>