"Think of all the time we spend manually organizing and performing mundane activities, from scheduling meetings to paying the bills," he writes in the foreword of Microsoft CEO Satya Nadella's new book, "Hit Refresh." "In the future, an AI agent will know that you are at work and have ten minutes free, and then help you accomplish something that is high on your to-do list." It won't just boost productivity in the office, either, says Gates: "Innovation will improve many other areas of life too." It could help wipe out polio, for example. And "digital money is letting low-income users save, borrow, and transfer funds like never before."

Other thought leaders agree with Gates: Facebook founder and CEO Mark Zuckerberg says AI is going to make our lives better in the future, and John Giannandrea, senior vice president of engineering at Google, says "machine learning and artificial intelligence is extremely important and will revolutionize many vertical industries." Gates, while optimistic about the future, doesn't brush aside the hard questions that must be addressed. "With every new technology, there are challenges," he writes. "How do we help people whose jobs are replaced by AI agents and robots? Will users trust their AI agent with all their information? If an agent could advise you on your work style, would you want it to?" But in general he has a positive outlook: "The world is getting better, and progress is coming faster than ever." Like this story? Like CNBC Make It on Facebook! Don't miss: Elon Musk: 'Robots will be able to do everything better than us'

