Rabbi Elazar resided in Safed at the time it was filled with a most incredible group of Halachists and mystics including R. Joseph Caro, R. Moshe Trani, R. Isaac Luria, R. Moshe Cordovaro, R. Moshe Alshich and R. David B. Zimra. According to Chida he was ordained by R. Yaakob Berab.
Rabbi Elazar founded a chavura called Sukkat Shalom, for whom he wrote his most famous work, the Sefer Chareidim. The Chareidim is organized around the 613 mitzvot which he divides according to the limbs of the body based on the verse all my limbs proclaim G-d- who is compared to Thee.
He emphasized the mitzvot of Eretz Yisrael and quoting the Ari, opposed extensive fasting for those who occupied themselves with Torah. He wrote a number of other works including a commentary on the Jerusalem Talmud. He composed the well known song Yedid Nefesh. He emphasized the importance of spending periods of time in solitude and meditation. The deeply moving Yedid Nefesh reflects his profound spirituality. There is an unpublished manuscript containing his meditation and revelations.
Rabbi Elazar states that a person is complete when he performs all 613 mitzvot. If so, he asks, there are many mitzvot which were not commanded to every Jew, how then can every Jew fulfill all the mitzvot? He answers that all Israel is one soul and those who encourage those upon whom it is incumbent to perform certain mitzvot are themselves credited with the mitzvot.
Sources: Orthodox Union