While already/not yet is a helpful tool to understand some passages, there are many promises that will find their primary fulfillment in this present age.
The Reign of Christ
One example of this is the reign of Christ. After his resurrection, Jesus ascended into heaven and sat down at the right hand of God.
“So then, after the Lord had spoken to them, He was received up into heaven, and sat down at the right hand of God” (Mark 16:19).
“Who being the brightness of His glory and the express image of His person, and upholding all things by the word of His power, when He had by Himself purged our sins, sat down at the right hand of the Majesty on high” (Hebrews 1:3).
At his first coming, Jesus was inaugurated as king. Presently, he is already reigning as king, but his reign is not yet perfect.
“Yahweh said to my Lord, ‘Sit at My right hand, Till I make Your enemies Your footstool’” (Psalm 110:1).
The Father’s intention is that Jesus reigns until all of his enemies are defeated.
“But this Man, after He had offered one sacrifice for sins forever, sat down at the right hand of God, from that time waiting till His enemies are made His footstool” (Hebrews 10:12-13).
“But each one in his own order: Christ the firstfruits, afterward those who are Christ’s at His coming. Then comes the end, when He delivers the kingdom to God the Father, when He puts an end to all rule and all authority and power. For He must reign till He has put all enemies under His feet” (1 Corinthians 15:23-25).
Jesus will remain in heaven ruling until his enemies are defeated. After this, he will return.
Again, our eschatology affects how we view this present age. Because we do not yet see all of Jesus’ enemies defeated, we do not expect Jesus to return yet.
This is the opposite of how most contemporary American Christians think. Many view the world as getting worse and worse and assume that this means that Jesus will return soon.
Yet, the exact opposite is true. Jesus will not return until all his enemies are under his feet. If we see evil triumphing on the earth, this is not a sign that Jesus’ return is getting closer. It is a sign that Jesus is not done ruling from heaven.