For a quick display purposes I generally use the Send Program Message (SNDPGMMSG) command with the MSG parameter set to the variable to be displayed. One consideration is that you need to first convert any non-character variables to character.
SNDUSRMSG <i>might</i> be a little less intimidating than SNDPGMMSG. Or SNDMSG TOUSR(*REQUESTER) can be even easier. The same ‘character conversion’ advice applies, though. At times, the most useful to me is DMPCLPGM inserted at one or more points in the program. A dump of all variables is spooled in the job and can be viewed like any spooled output.
If the purpose is for user interaction, then perhaps an actual display file is called for. Declare the file with DCLF and use SNDRCVF like you would use EXFMT in RPG.