In that case, I would recommend either the Basic Parser, or the Pattern Parser with a broadly defined format.
You should be able to configure a Pattern Parser with something like:
%d %m%n
%d: %m%n
%d{yyyy-MM-dd HH:mm:ss.fff} %m%n
Basically, just a date (%d) a message (%m) and an end of message (%n). Defining the date format is useful if you are dealing with large log files and more accurate file parsing - but it is not required. If there are log messages you would like to parse, consider a Message Parser (which is separate from the log file parse).