You need a loop of some kind - either explicit like
foreach
,
for
, or
while
; or implicit as with a Linq query:
string findEm = "raj, kumar, csd";
List<string> matches = new List<string>() {"raj", "ASDF", "EJSDA", "ARHS"};
IEnumerable<string> found = findEm.Split(", ").Intersect(matches);