3 Your people shall be volunteers In the day of Your power; In the beauties of holiness, from the womb of the morning, You have the dew of Your youth. Psalm 110:3
12 For the seed shall be prosperous, The vine shall give its fruit, The ground shall give her increase, And the heavens shall give their dew— I will cause the remnant of this people To possess all these. Zechariah 8:12
17 Love has been perfected among us in this: that we may have boldness in the day of judgment; because as He is, so are we in this world. 1John 4:17
The renewal of one's youth as the eagle's, in the language of Psalm 103, is one of the fundamental benefits of the doctrine of Christ, even if not one of it's fundamental principles. In Scripture, by virtue of the nature of redemption, principles of the doctrine of Christ become benefits as they are lived out.
While some might ask why we are to understand this as youthfulness in Psalm 110 rather than as children or new initiates into the Christian faith, this is clarified from the very nature of dew as fleeting, as among the most fleeting of phenomena, and never as something that grows into a full body of water. Dew meets a need rather than ever being understood to be the seed of an entity.
Here is the Psalms and the prophets and from the very nature of redemption, including our being joint-heirs with Christ, if we resist temptation with Him, according to Romans 8:17 and Hebrews 2:18, refusing to yield to those things we've been bought back from by His sufferings, then to us the heavens are to give the dew of our youth. Translation: perpetual youth. That's the bottom-line. Youth that never goes away if it's Christ's.
Perpetual youthfulness is, therefore, one of the more advanced doctrines of the New Testament because Psalm 110 makes it a part of the Melchizedek reign that we are joint-heirs of as ministers to the nations. The heavens shall give their dew as we maintain open heavens in our lives. In the New Testament, living and reigning with Him a thousand years is the first-fruits of the Spirit on living with Him and reigning with Him until the 1Corinthians 15:28 abdication, when you compare the fourth verse of Revelation 20 with the ages of ages we reign with Him in Revelation 22:5 because of the seal of the Spirit in the fourth verse.