Do these verses say everyone can be perfect and free from sin and Jesus did not HAVE to suffer for us?

how would you gain underatanding if not by listening to Christ and His word? And how would you find the kingdom of God without believing in our Lord and Saviour Christ Jesus? and you cant save yourself from evil or create a clean spirit within you, by yourself either.And by the way the pharisees also thought they were righteous, as they after all obeyed the laws of Moses, or so they said, and they sought to kill Him.