God is eternal and He is Spirit. He is alpha and omega, the beginning and the end, the first and the last.
He is living, He always has lived and He ever will live.
All life issues from the Holy Spirit who is the eternal Spirit Of God.
When scripture refers to the living God they are emphasizing the fact that He is the source of life.
Hebrews named the Living God, YHVH, which is the sound of inhaling and exhaling - evidence of life.
In the Lord Jesus Christ we come to know the Truth about the LivingGod because His body was
→ formed by His Holy Spirit,
→ filled with His Holy Spirit
→ inspired by His Holy Spirit
→ empowered by His Holy Spirit and
→ raised by His Holy Spirit.
This is why Jesus referred to Himself as the Truth. He has revealed the nature of the LivingGod to us in His Words, His deeds, His sacrificial death and His glorious resurrection.
This LivingGod is the Lord Jesus Christ who is the personification of the Spirit Of God and the Soul Of God in the Body Of God.
There is no other God, living or dead, other than the Lord Jesus Christ.