Just a couple of things:
We must remeber that this is all in the old covenant, wich the law (second to the fifth book in the bible) is everything, the principles of the law is you reap what you sow, eye for an eye witch ar hard rules and can end with hard results.Love you brethren but hate you enemy. The Amalkites had chosen to follow the devil instead of God, and therefore they and there famlies where doomed.
This makes what Jesus did even more wonderful, he who forfilles the law, and comes with and escape from the coming doom, and brings peace and tells us to love our enemies and even turn the other cheek.
Second of all, you can not qvote just a couple of verses, you must read it all in contex with the rest of the Word of God.
And yes, you must have the Holy Spirit right there with you if you want to know what God wants to say, there are many people who reads the bible and know it from a historicaly point of view but rejeckt it’s divinity.
So the sum (not just single verses taken out of contex, even Hitler quoted the bible you know)of God’s word is true, and it can only be read right with the goggels of prayer and with the guidance of the Holy Spirit, The One of the trinity who is actually here right now preforming all sorts of miracles.
Let us put down childish discussens and rejoys together i Christ Jesus instead og judging each other, all living (and former living) people must stand in front of God ALONE, so let us prais God together and be filled with the Holy Spirit and build eachother up instead.
God bless you all