A common passage of encouragement among Christians is Isaiah 40:30-31:
Though youths grow weary and tired, and vigorous young men stumble badly, yet those who wait for the Lord will gain new strength. They will mount up with wings like eagles. They will run and not get tired. They will walk and not become weary.
In the context of this verse, Isaiah was correcting Israel for her failures: for failing to trust in God for salvation, failing to believe in God’s omnipotence in all things, and failing to look to God for the strength He would surely supply. Rather, Israel believed that her own strength was sufficient. To answer those weaknesses, Isaiah gives answers the strong Christian would be wise to follow. Christians must wait upon the Lord and in waiting, we will get strength from God so that we can handle the trials of our life. The strong Christian will never tire of doing God’s work, but will always have strength through the power of God, for God’s true servants will be filled with His grace.
This passage speaks in very pictorial language by comparing Christians to eagles because the use of such imagery helps us to remember our Creator. Ralph Erskine comments on this passage by noting that
… the wings of the eagle are the gracious works of the Holy Spirit in our lives. The first wind is that of faith; the second is love. These wings bind us to Christ with such power nothing can overcome them, and they allow us to soar to heaven. Now, we do not mount up to heaven with theoretical knowledge, which even devils have, nor do we seek to know the secrets of election and reprobation, although if we belong to Christ our election is sure. We also do not mount up in spiritual pride, nor in transient times of affection, but in humility of spirit. Hughes Oliphant Old, Holy Communion in the Piety of the Reformed Church, p. 551-552.
By meditating on the things of God, we rise up, seeking to serve the Lord in all we do and looking for His face wherever he may be found. Daily, the true Christian seeks to become more sanctified, to deepen his/her piety before the Lord, and to share His heart. The believer does rise up continually through the Christian life.
This rising begins at conversion when we find ourselves to be the children of God, and we continue without interruption to wake up in the arms of Christ. When the Spirit sends his breath of influence upon us daily, we experience growth. Likewise, when we come to the Lord’s Table, we seek nothing less than the heart of Christ, which beats out love for us, and we hold him in our arms forever.
This rising of the soul is natural to the believer, who has been set free and seeks to rise higher and higher into the grace of God. Nothing will stand in the way of this rising of soul, for the strength and determination overcomes everything else. The rise is gradual, for there is much to learn, and it continues on a daily basis as we seek to know God better. We do this because of our new nature, which has come from heaven and wants to return there. The sight of this heavenly reality makes us seek it more even on earth, for there is our safety, affection, and treasure. Furthermore, as we come to the Lord’s Table, and partake of His goodness, our strength for this flight is renewed. This is why Holy Communion is above all a feast of covenant renewal. Therefore, as Christians, we daily seek to be nourished by the Word, and on the Lord’s Day, we feed on the Lord so that our hearts remain fixed in heaven.