Torah portions are an ancient tradition that was started back in the time of Nehemiah and Ezra. When the Israelites returned from captivity, they wanted to make sure they didn't end up there again. They knew it was their disobedience that had gotten them into trouble. So, they created a weekly Torah reading schedule to make sure that everyone would hear the Torah read through once per year. This is the same schedule Yeshua (Jesus) followed when He walked the earth, and it's the same schedule followed today.