"For the earth shall be filled with the knowledge of the glory of the Lord, as the waters cover the sea" (Habakkuk 2:14).
The very first command given to Adam and Eve was: "Be fruitful, and multiply, and replenish the earth . . ." (Genesis 1:28). This might seem to imply there had been a previous population (so-called "pre-adamites") but the word "replenish" (Hebrew, male) means simply "fill." Actually, in the King James Old Testament, it is translated by the Old English word, "replenish," only seven times, whereas it is translated "fill" or "filled" or "full" some 250 times. The precise meaning is "fill."
Even today, with our so-called "population explosion," the earth is far from being filled with people. One thinks of our vast deserts, and inaccessible mountain ranges, plus the frozen wastes of Antarctica, for example. It may, however, once have been filled in the much more habitable world before the Flood, but it also was "filled with violence through them" (Genesis 6:11,13). This, in fact, was the very reason God sent the great Flood to "destroy them with the earth."
The time is coming, however, as seen in Nebuchad-nezzar's prophetic vision, as interpreted by Daniel the prophet, when a great stone-representing the future kingdom of God-will have "filled the whole earth" (Daniel 2:35). Then the great doxology of the psalmist will be reality. "And blessed be His glorious name for ever: and let the whole earth be filled with His glory; Amen, and Amen" (Psalm 72:19).
The prophet Isaiah also spoke of this time. "They shall not hurt nor destroy in all my holy mountain: for the earth shall be full of the knowledge of the Lord, as the waters cover the sea" (Isaiah 11:9). The later prophet Habakkuk in our text, beautifully echoed these words of Isaiah. HMM