"but he has been made alive again." "Raised" here is an idiom for "caused to live again." This can be stated in active form. AT: "because God has made him alive again" (See: [[rc://en/ta/man/translate/figs-activepassive]] and [[rc://en/ta/man/translate/figs-idiom]])
This is the beginning of an indirect quote. It can also be translated with a direct quote as in the UDB. (See: [[rc://en/ta/man/translate/figs-quotations]])
The phrase "must be" means this is something that would certainly happen because God had already decided that it would happen. AT: "it was necessary that they hand the Son of Man over to sinful men who would crucify him" (See: [[rc://en/ta/man/translate/figs-activepassive]])
The Jews counted any portion of a day as a day. Therefore, the day Jesus was raised was the "third day" because it followed the day of his burial and the Sabbath day. (See: [[rc://en/ta/man/translate/translate-ordinal]])