Definition:
Immediate glorification refers to the theological concept that believers in Jesus Christ are instantly transformed and glorified upon their entrance into eternal life, typically understood to occur at the moment of death or at the return of Christ. This transformation involves the believer receiving a glorified body and entering into the full presence of God.

Biblical Basis:
The concept of immediate glorification is rooted in several passages of Scripture that speak to the transformation and glorification of believers. In 1 Corinthians 15:51-52 , the Apostle Paul writes, "Listen, I tell you a mystery: We will not all sleep, but we will all be changed—in an instant, in the twinkling of an eye, at the last trumpet. For the trumpet will sound, the dead will be raised imperishable, and we will be changed." This passage suggests a sudden and complete transformation at the return of Christ.

Philippians 3:20-21 further supports this idea: "But our citizenship is in heaven, and we eagerly await a Savior from there, the Lord Jesus Christ, who, by the power that enables Him to subject all things to Himself, will transform our lowly bodies to be like His glorious body." Here, Paul emphasizes the transformation of believers' bodies to be like Christ's glorified body, indicating an immediate change upon His return.

Theological Implications:
Immediate glorification underscores the hope and assurance of eternal life for believers. It affirms that upon death or Christ's return, believers will be fully sanctified and made perfect, free from sin and its effects. This belief is rooted in the promise of eternal life and the ultimate redemption of both soul and body.

Romans 8:29-30 provides a framework for understanding this process: "For those God foreknew, He also predestined to be conformed to the image of His Son, so that He would be the firstborn among many brothers. And those He predestined, He also called; those He called, He also justified; those He justified, He also glorified." The progression from predestination to glorification highlights the certainty and completeness of God's redemptive work.

Practical Considerations:
The doctrine of immediate glorification offers comfort and encouragement to believers facing death or the loss of loved ones. It assures them that death is not the end but a transition into a glorified state in the presence of God. This hope is reflected in 2 Corinthians 5:8 , where Paul expresses confidence: "We are confident, then, and would prefer to be away from the body and at home with the Lord."

Furthermore, the anticipation of glorification motivates believers to live holy and godly lives, as they await the fulfillment of God's promises. In 1 John 3:2-3 , the Apostle John writes, "Beloved, we are now children of God, and what we will be has not yet been revealed. We know that when Christ appears, we will be like Him, for we will see Him as He is. And everyone who has this hope in Him purifies himself, just as He is pure."

Conclusion:
Immediate glorification is a key aspect of Christian eschatology, emphasizing the believer's ultimate transformation and union with Christ. It provides a source of hope and motivation for living a life that reflects the character and holiness of God.