Eternity implies the absence of beginning, end, and temporal succession in God. This concept is hard not only to understand, but also to express. Eternity never begins and it never ends. God’s duration is as endless as his essence is boundless. He is the everlasting God (Gen. 21: 33; Rom. 16: 26). If he has no beginning, he certainly has no end (see Psa. 9: 7; 52; Rev. 4: 9– 10). Since he needs nothing, he cannot pass out of existence. For him there is no past or future, but only a simple present in which he sees all things, past, present, and future, at once. He receives nothing as an addition to what he was before. He does not ever become something he was not before. He was perfect before all ages and will be so after all ages. He is what he always was; he will be what he will always be. He inhabits billions of years in one moment, and each moment is to him billions of years, in a manner of speaking. Jesus possesses this attribute of eternity. He is the ‘Ancient of Days’ (Dan. 7: 9, 13, 22).
Mark Jones. Knowing Christ (Kindle Locations 721-727). The Banner of Truth Trust.