Brahmanas are the symbol of spiritual education, and cows are the symbol of the most valuable food (milk production & Butter); they must be given all protection.. that is real advancement of civilization.
A devotee knows that even at his death Krishna will protect him. The real test of our devotion will be at that time.
If God wants to kill somebody, nobody can protect him and if God wants to protect him, nobody can kill him.
The Lord protects everyone, but one who depends completely upon Him is especially looked after by the Lord.
Srimad Bhagavatam 1.8.8,
A devotee of the Lord is always fearless because of the protection given by the Lord.
To protect ourselves from Kali we have to be honest, sincere and should not keep ulterior motive-. Hence we became instruments of Maya. We should strive to live by the teachings that Srimad Bhagvatam has left with us.