Problem: Jesus said here, “I and My Father are one.” But on other occasions He distinguished Himself from the Father, saying “I came forth from the Father and … I leave the world and go to the Father” (John 16:28). Further, He prayed to the Father as one person to another (John 17), and even said, “the Father is greater than I.”
Solution: Jesus was one with the Father in nature, but distinct from Him in person. The triune Godhead has one essence, but three distinct persons (see comments on John 14:28). So, Jesus was both the same in substance and yet was a different individual from the Father.