How do I do a recursive grep?

How do I do a recursive grep?

           a. Method 1 (recommended)
               1. /usr/bin/find . | /usr/bin/xargs /usr/bin/grep PATTERN
               2. displays filename:match
           b. Method 2 (recommended)
               1. /usr/bin/find . -exec /usr/bin/grep PATTERN {} /dev/null \;
               2. displays filename:match

Ex:
bash-3.00# find /tmp | xargs grep "RTMAX"
/tmp/nsig:RTMAX-3       default
/tmp/nsig:RTMAX-2       default
/tmp/nsig:RTMAX-1       default
/tmp/nsig:RTMAX default