Being "born again" represents the transformation which takes place when one gives up the old way, the old paradigm ("me first"), exchanging it for God's way, ("agape"), captured by the phrase, "Not I, but Christ." This is evidently conversion.

What word do you use to describe the person who has progressed to obeying and observing everything Jesus commanded?

I use the word converted. That is, they have completed the process of converting from the ways of the world to the ways of Jesus.

How, then, are we to be saved? "As Moses lifted up the serpent in the wilderness," so the Son of man has been lifted up, and everyone who has been deceived and bitten by the serpent may look and live. "Behold the Lamb of God, which taketh away the sin of the world." John 1:29. The light shining from the cross reveals the love of God. His love is drawing us to Himself. If we do not resist this drawing, we shall be led to the foot of the cross in repentance for the sins that have crucified the Saviour. Then the Spirit of God through faith produces a new life in the soul. The thoughts and desires are brought into obedience to the will of Christ. The heart, the mind, are created anew in the image of Him who works in us to subdue all things to Himself. Then the law of God is written in the mind and heart, and we can say with Christ, "I delight to do Thy will, O my God." Ps. 40:8. {DA 175.5}