He is using the Bible that all Christians use.

Jeff Sessions quoted Romans 13:

“13 Let everyone be subject to the governing authorities, for there is no authority except that which God has established. The authorities that exist have been established by God. Consequently, whoever rebels against the authority is rebelling against what God has instituted, and those who do so will bring judgment on themselves. 3 For rulers hold no terror for those who do right, but for those who do wrong. Do you want to be free from fear of the one in authority? Then do what is right and you will be commended. For the one in authority is God’s servant for your good. But if you do wrong, be afraid, for rulers do not bear the sword for no reason. They are God’s servants, agents of wrath to bring punishment on the wrongdoer. Therefore, it is necessary to submit to the authorities, not only because of possible punishment but also as a matter of conscience.”

Using that line of reasoning anything that the government does could be justified. People find things that justify the most immoral president ever. He could shoot someone in the middle of the street and people could justify it using that scripture. The Bible is full of contradictions and immorality just like Sessions and his boss are.