Not sure if this is the easiest or best way to go about this, but it works for me. Try copying your two columns to another worksheet.
1. Change the font color of column A
2. Cut column A and paste it in column B, underneath the last value in this column.
3. Sort Ascending (A-Z) Now you should have just one column containing all data.
4. In the next column over, insert this formula - IF(B1=B2,"Match","")
Hope this works for you.