さがす (sagasu) means "to search for", 見つける (mitsukeru) means to "find". In English, there is a difference between the two. However, in some cases, what we "look for" in English, we "find" in Japanese.
Shigoto wo mitsukeru (not sagasu) no wa muzukashii darou to omou.
I think looking for a job is difficult.
(Although, finding a job is actually more difficult!)
さがす (sagasu) is also for concrete things. For abstract things like happiness and peace, 求める (motomeru), which means "seek", should be used.
Ooku no hito ga koufuku wo motomete iru (not sagashite iru).
Many people are looking for happiness.