After the first sin, guardian angels were assigned to us by God. They were not so much to guard us as to guard paradise against us so as to prevent us from re-entering it. We were cut off from life by angels, fire, and a sword.
After thousands of years during which we had been banished from paradise, Jesus, the new Adam, re-opened the gate of paradise and even the gates of heaven by His obedience even to death on the cross (Phil 2:8; Rm 5:18-19).
Jesus' Incarnation was announced by the Archangel Gabriel (Lk 1:26), and angels sang at His birth (Lk 2:13ff). Angels were used by Jesus to re-open paradise rather than to keep us out.
Jesus used the fiery tongues of the Holy Spirit to break down the barrier separating us from paradise, God, and one another (Acts 2:3).
Jesus has given His disciples the "sword of the Spirit" by which they can resist the evil one (Eph 6:17), who originally seduced us to sin and thereby to lose paradise.
Jesus has reversed the original sin and restored us to "paradise plus." Jesus is our Savior, our only Hope, our Lord, our God.