You may need to rearrange the parts of this sentence, which begins in verse 32. "God has fulfilled for us, their children, the promise that he made to our fathers, by raising up Jesus" (See: [[rc://en/ta/man/jit/translate-versebridge]])
"for us, who are the children of our ancestors." Paul is still speaking to the Jews and Gentile converts in the synagogue at Antioch of Pisidia. These ancestors were the physical ancestors of the Jews and the spiritual ancestors of the converts.
Here to raise up is an idiom for causing someone who has died to become alive again. Alternate translation: "by making Jesus alive again" (See: [[rc://en/ta/man/jit/figs-idiom]])