Chay means living, alive, or life. It appears about 500 times. It describes living creatures, the state of being alive, and most significantly — the 'living God' who is active and present among His people.
The epithet 'the living God' distinguishes YHWH from dead idols. God is the source of all life, the 'fountain of living waters' (Jeremiah 2:13). The tree of life in Eden and the water of life in Revelation bracket Scripture with this concept. To know God is to have abundant, eternal life.