John 7:19 "Did not Moses give you the law, and yet none of you keepeth the law? Why go ye about to kill me?"
These Jews prided themselves on their observance of the law, but they were keeping the letter of the law and missing its true intent. The greatest of all the Old Testament laws was to love God and then to love your neighbor as yourself. The Jews were violating these laws by having hatred in their hearts toward Jesus and wanting to kill Him. They denied that they desired to kill Him, but the scriptures declare that they had already plotted or tried to kill Him three times.
They also knew much about God. It was required of the Jewish men to memorize large portions of the Torah (the first five books of the Bible). Their whole society revolved around God's moral standards and countless religious observances. However, they did not know God.
There is a difference between knowing about someone and really knowing them. Likewise today, millions of people are acquainted with knowledge about Jesus. They may even be moral and observe religious ceremonies, but if they don't personally experience knowing Jesus, they are not saved and will not make it to heaven. Even the devils believe and tremble but they aren't saved.
Our spiritual man became dead unto (separated from) God through sin. Just as we didn't accomplish our physical birth, we cannot produce this spiritual rebirth. We are totally incapable of saving ourselves, therefore, we need a Savior. We simply believe on the Lord Jesus Christ and we are saved.
Salvation is not a reformation, but rather a regeneration, a new birth, a new creation, that can only be accomplished by a creative miracle of the Holy Spirit. You must be born again.