All living beings are able to become a Buddha, but they all become a Buddha in a different way, and each Buddha teaches in a different way. A wise teacher, when he or she looks at their disciples, is able to see which path each disciple will follow in the future and the realization they will attain, and with this knowledge the teacher can help their disciples have more confidence and follow the right path. Giving a prediction is a transmission of spiritual energy from teacher to disciple.