Bush, who has had many speaking engagements since moving to Dallas after his presidency, said he doesn't plan on staying in the public eye.
"You won't see me out there opining ... or criticizing my successor," Bush said, later adding that he is writing a book about his decisions in office so that "you can draw your own conclusions."
His speech touched on various topics, including the war in Iraq, 9-11, foreign policy, the economy and faith-based programs -- as well as previous presidents and the relationship with his father, former President George H.W. Bush.
Bush said he was guided in part by the principle that democracy yields peace.
"It's in the interest of the United States to promote freedom -- all places, all times," he said.
Bush said he remained "in awe" of U.S. troops and that his numerous meetings with families of troops killed in the war were uplifting.
"The U.S. is full of people who will do what it takes to protect the United States," he said.
Fort Worth Christian School's president, Kelly Moore, said school officials wanted Bush to speak because he was a leader in education as Texas governor and then as U.S. president. The school has more than 860 students.
Moore noted that Bush "has exhibited the qualities of leadership and great faith."
Students presented Bush with a $5,000 check from their fundraising efforts to help earthquake-ravaged Haiti. Recently, President Barack Obama enlisted Bush and former President Bill Clinton to spearhead private fundraising efforts to rebuild Haiti.
