Among various periods or epochs in the history of mankind, most students distinguish an age of innocence before Adam sinned, Rom. 5:12; an age of law and an age of grace, Rom. 5:20, 21; a future kingdom age, Matt. 25:34; and “the ages to come,” which follow other ages, Eph. 2:7; 3:5. Some would add an age of conscience, Gen. 3:7-8:22; an age of human government, Gen. 9:6; and an age of promise, Gen. 12:1-Ex. 19:4. The tribulation is sometimes regarded as a separate age, Matt. 24:21.
God’s plan for His church was not made known in earlier ages, Eph. 3:4-6; Col. 1:26. One revealed purpose for the present offer of salvation by grace is to make it possible for God ultimately to show the riches of His grace in His kindness toward us through Christ Jesus, Eph. 2:4-7.
The Greek word for age is translated world some 29 times in the AV, as in Matt. 13:39; Rom. 12:2. The margin corrects this in many places. For example, Heb. 9:26, “now once in the end of the world hath he appeared,” has been changed in the RV margin to state that He came “in the consummation of the ages.”
The Bible doctrine of the ages during which the divine purposes unfold emphasizes the antiquity and variety of God’s program, while revealing that it is to have an unending extension in eternity future.
William Evans, The Great Doctrines of the Bible, (Chicago: Bible Institute Colportage Assoc., 1912), WORDsearch CROSS e-book, Under: “Ages”.