There are so many things that happen spiritually but the devil wants us to be blind so we do not see. The two disciples of Jesus were spiritually blind but after the Eucharist their minds were opened and were ready to overcome the devil.
When Jesus said the Son of Man be lifted up everyone who looks at him and believes shall have eternal life. The serpent itself was a symbol of sin, Christ was made sin for us that we might be made free from sin (2 Corinthians 5:21). When we disobey God those actions are sins. The power or force that makes me disobey God is sin. If we do not have the power of sin we can never commit sins. God forgives us of our sins which means our actions against God have been cancelled but the nature of sin is still there.
That nature came through Adam who got rid of the image and likeness of God. Jesus died our death and when God raised him, we were raised with him. The cross of Jesus destroyed sin; the blood of Jesus forgives them. The nature of sin is no longer there in our spirit because we have died with Christ; therefore we have the nature of Christ in us.
The Word of God cleans our mind so that we can rid our mind of the knowledge of sin and live in righteousness. The bible says to love our enemies; it will not be easy, the bible also says to give the other cheek when we get slapped on one. When we make the decision to walk in love, the power to act in love comes from our spirit. This is why we are able to do things above and beyond our capacity because it is done through the Holy Spirit.