You won't find a Scripture that says God is for or against a Christian being a soldier. From my knowledge of the Bible, I'm convinced that God isn't against a Christian being a part of the military. The New Testament speaks very positively concerning those that are in the military.
Notice what was told to soldiers via John the Baptist.
Then some soldiers asked him, "And what should we do?" He replied, "Don't extort money and don't accuse people falsely - be content with your pay."The Bible isn't telling them to leave the military because it is evil or wrong. It's simply telling them not to use their military positions to extort money from helpless people.
(Luke 3:14 NIV)
We have another account of a military man being dealt with by the apostle Peter. This man's name was Cornelius. He was a captain over one hundred men. God sent an angel to Cornelius telling him to send for Peter. The angel said that Peter would tell him words whereby he could be saved.
When Peter came to speak to Cornelius, God saved him and filled him with the Holy Spirit (Acts 10:1-48). He didn't tell this military man, "If you change your ways and get out of the military I'll allow you to become a Christian." He simply permitted him to be saved and filled with the Holy Spirit.
It's also important to note that Cornelius wasn't told to leave the military after he received salvation. I believe that a Christian can be a part of the military as an honorable profession.
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