18 But we all, with unveiled face, beholding as in a mirror the glory of the Lord, are being transformed into the same image from glory to glory, just as by the Spirit of the Lord.
This verse continues Paul’s exposition of Exodus 34:33-35, whereby Moses removed his veil when he went before the Lord. This symbolized his boldness before the Lord. Verse 18 draws an analogy to what happen to Moses–Christians also can approach God with an unveiled face. By doing this they are in the process of transforming into the glory of Christ.
18 But we all [emphatic],
The “all” here are Christians in the New Covenant of grace in contrast to the hardened Jews of the Old Testament. These are those who have the indwelling Holy Spirit residing in them.
with unveiled face,
Like Moses unveiled his face before the Lord, the Christian can approach God with boldness. The Holy Spirit removed the veil of the Law to reveal the glory of the New Covenant. Lifting the veil represents liberty to fellowship with God.
beholding [oneself] as in a mirror the glory of the Lord,
As the believer devotes himself or herself to reading Scripture, they will see God’s glory reflected in Christ (2 Co 11:3). What Christian see in the mirror of God’s Word is the Lord. When this happens, gradual spiritual transformation occurs. As we advance in Christlikeness by the Spirit, our character will reflect His glory (2 Pe 3:18).
There is a difference between the purpose of the indwelling of Christ and the indwelling of the Holy Spirit. Christ dwells in us to manifest His glory (Jn 14:18-21; Ro 8:10). The Holy Spirit dwells in us so that Christ can take up His royal residence there.
The Christian transforms into the glory he has seen.
The Christian is transformed as he or she contemplates the glory of God in Christ. That glory creates a reflected glory in the believer.
The Bible refers to itself as a “mirror” (Jas 1:23-25). When sinful people study the Bible, they see their sinfulness. They see Christ’s image in comparison to their own. This is disconcerting to those who do not want to allow God to convict them of their sin. It exposes them for what they are. A mirror reflects what it sees. The Bible faithfully reflects what we are; it exposes our spiritual deficiencies.