Yes… the God of Israel killed people but He never murdered them. And the way Jesus lived is how God always lived but when He came in the flesh He came in weakness for the purpose of submitting Himself under the powers of evil instead of ruling over the powers of evil as He did in the OT, which can only be accomplished by violent force. Jesus was the God of Israel and killing is not murder. There are a lot of different views among Christians. This “God of the OT was a murderer” is one of them.
Jesus lived how He always lived. He was exactly the same person in appearance as the one who appeared to Abraham by the terebinth trees of Mamre along with two others who dined on bread, butter, milk and meat. It was Jesus who wrestled with Jacob and changed his name to Israel. It was Jesus who appeared to Moses Aaron, Nadab, and Abihu, and seventy of the elders who, “saw the God of Israel.” And they saw “under His feet as it were a paved work of sapphire stone, and it was like the very heavens in its clarity.” It was Jesus who appeared to Joshua with His sword drawn in His hand and said He was the “Commander of the army of the LORD.”
All of these men from Abraham to Jacob if they would have lived during the time of Christ would have fell on their faces as soon as the saw Him because they would have recognized Him. Jesus is the God of the OT and He never murdered or sanctioned the murder of anyone. If you and your contingent of Christians can’t understand this then there’s little more I can say to convince you.
I do however agree with your view about joining the military And yes…” killing without God as the leader, is murder.”