It really depends what song you are making the loop for.  In general, a loop should have a sufficient number of elements to keep it interesting and add real value to a worship band using it.  A single pad or beat track for an entire song would probably not be enough and your submission may be rejected. In general (IN GENERAL) most tracks have some type of beat/percussion, pads, and something else (either strings, piano, guitar, bells, synth lead etc.) that adds flavor to the song. If you're unsure, just submit a support request and we'll point you in the right direction!