Many people visit the Holy Land every year, so it's certainly safe as long as you keep a few precautions in mind. A lot of it just comes down to prudence and common sense, really: You should definitely take a tour with an experienced guide. Read the travel advisory pages for Israel and its neighbors published by the U.S. State Department. You can find the advisory page for Israel here. Avoid crowded public transportation and public markets. Avoid demonstrations and sites with significant religious meaning to multiple faiths like the Temple Mount. Don't visit or photograph military areas. Also take care not to photograph the police, religious Muslims, and Orthodox Jews. Don't travel to the Gaza Strip. The West Bank should also be avoided. Take care to dress appropriately and mind religious customs, especially around ultra-Orthodox neighborhoods.