sermon on the mount--new covenant righteousness

But I say unto you

In Matthew 5:20, Jesus indicates that in order to be in the kingdom, one must have a righteousness that surpasses that of the Pharisees. Jesus then goes on to present six different scenarios from the Torah, demonstrating how the traditional Rabbinic application of the law is inadequate (vs. 21-22, vs. 27-28, vs. 31-32, 33-34, vs. 38-39, vs. 43-44). In each reference to the Torah, Jesus go beyond the physical commandment to unveil the spiritual law, indicating what it looks like when one transcends Pharisaic righteousness.

Which is harder to maintain, Pharisee righteousness or New Covenant righteousness? 

Can you have New Covenant righteousness without also having the righteousness of the Pharisees?

Daniel