"Even from everlasting to everlasting, thou art God" (Psalm 90:2).
God would not be God if He were not "from everlasting to everlasting." The eternality of God is a very essential aspect of His total being or make-up. It is part of that which makes up God as God.
Therefore each member of the Godhead, the Father, and the Son, and the Holy Spirit, is seen in Scripture to share this attribute of eternity. The Father in Deuteronomy 33:27; "The eternal God is thy refuge." The Son in Micah 5:2; "whose goings forth have been from of old, from everlasting," and, "Jesus Christ the same yesterday, and to day, and for ever" (Hebrews 13:8). The Holy Spirit in Hebrews 9:14 described as the "eternal Spirit." The Trinity has been defined as three eternal distinctions in one Divine essence.
Since God is eternal, His blessings to His own are eternal as well. "But the mercy of the LORD is from everlasting to everlasting upon them that fear Him" (Psalm 103:17). The New Testament speaks of Jesus procuring "eternal redemption" (Hebrews 9:12) for us through the shedding of His own blood, resulting in "eternal salvation" (Hebrews 5:9): Thus we have a new home, "a building of God, an house not made with hands, eternal in the heavens" (II Corinthians 5:1); an inheritance, "they which are called might receive the promise of eternal inheritance" (Hebrews 9:15), and a "far more exceeding and eternal weight of glory" (II Corinthians 4:17).
But those who know the Lord can say with David, "Blessed be the Lord God of Israel from everlasting to everlasting: and let all the people say, Amen" (Psalm 106:48). NPS