2 Corinthians 3:18 English Standard Version (ESV) And we all, with unveiled face, beholding the glory of the Lord,[reflecting the glory of the Lord] are being transformed into the same image from one degree of glory to another.[from glory to glory] For this comes from the Lord who is the Spirit.
Spending time with new believers and getting to know them gives us an opportunity to see them change. They may not even be aware of it themselves. As their former lives fade and the new life in Christ appears it is encouraging to know their salvation is real and the work of the Lord is alive in them.
Over the years we may also wake up to the knowledge that we ourselves have changed without a complete understanding of just how it happened. This come from the Lord who is Spirit. As was said yesterday, He is Lord and has not relinquished authority over us. Being gentle and kind some changes are initiated without our involvement. Other things need to be changed by repentance. Our actions are a reflection on Him and when our behaviors reflect badly on Him, then discipline is required.
Hebrews 12:11 English Standard Version (ESV) For the moment all discipline seems painful rather than pleasant, but later it yields the peaceful fruit of righteousness to those who have been trained by it.
It might seem like a great mystery as to how we are changed without our understanding but it might be just as simple as spending quality time with God in His Word. Even the oldest and most transformed among us spend time reading their bibles with a loving respect. It is a good habit developed over decades of a loving relationship with God.
We tend to do what we love.