The book of Malachi ends with a prophecy about the one who will foretell Christ (Malachi 4:5-6), then there is 400 years of silence between the Old and New Testament.
God looks at us and says, “very good,” He deems man so valuable He gave His son to bring man back into relationship with Him.
No one is too young, too old, or too busy to make their life count. Seek first the Kingdom of God.