Displaying Errors/Messages from MessageContext in JSP/JSTL

I am able to display the messages using message context in my jsp. but the error message will not be retained if you refresh the page.

Is
requestContext.getMessageContext().addMessage(new MessageBuilder().error().defaultText("error msg").build());
same as putting the error message in request scope?
What should i be doing if i want to retaine the error message even after refreshing? Or how can i save MessageContext object in flow scope as its not Serializable (flow scope can store only Serializable objects) ?:confused:

Thanks in advance.