The Great Exchange
Because Jesus is God, His very nature is higher than the angels. Yet for our redemption, Christ became lower than the angels for thirty-three years.
Hebrews 2:9 But we see Jesus, who was made a little lower than the angels for the suffering of death, crowned with glory for the suffering of death, crowned with glory and honour; that he by the grace of God should taste death for every man.
When we place our faith and trust in Jesus we make an exchange -- our sin for Christ's righteousness. Our sin was poured into Christ at His crucification and His righteousness is poured into us at our conversion. "The Great Exchange" -- What a deal!
2 Corinthians 5:21 For he hath made him to be sin for us, who knew no sin; that we might be made the righteousness of God in him.
It is because of God's grace -- God giving us what we do not deserve -- and God's mercy -- God withholding what we do deserve -- that we have salvation.