To show the world what to expect and how to resist the devil. Satan can quote scriptures but he uses them in his own way.  He can easily get us to believe him and turn us away from God.

Jesus was obedient to His Father and by reading His Word and trusting in Him we too can be obedient and avoid temptation.

For those who did not believe Jesus was the Son of God they got what they wanted, they released a convicted murderer and put Jesus in his place because they wanted Jesus crucifed.

Jesus death benefit all who believe because He died for us, for our sins. He died that we might have life in abundance.  His death benefit us because in this world of impossibilities, He makes it all possible, He is in control of everything, by His stripes we are healed.