Why can no power on earth or in heaven separate us from God's love?

Les explains that because Adam fell, God lost us and must redeem us, and redemption comes only by blood—the one thing God can use to purchase mankind’s redemption. Christ Jesus was sent to be a propitiation through faith in His blood, and the only way to experience that redemption is by putting faith in the blood of Christ. That is why Paul goes back to the Passover night in Egypt: just as the Jewish family in Egypt was safe and the death angel could not touch the firstborn because of the blood on the door, so those who have had Christ’s blood applied cannot be touched. Les then points to Romans 8, where Paul says we are more than conquerors through Him who loved us and is persuaded that neither death, life, angels, principalities, powers, things present, things to come, height, depth, nor any other creature can separate us from the love of God in Christ Jesus. The reason is that we are under the blood, and no power on earth or in heaven can take us from under that blood protection; as Israel was safe in Egypt, believers are safe today.