Christ did not disavow the Old Testament en toto.
Oh dear, clearly you didn't read what I told you to. Allow me to quote Jesus' own words from Matthew 5 "Until Heaven and earth pass away, not the smallest letter or stroke shall pass away from the law, until all is accomplished."
But perhaps that isn't clear enough for you? Here's a quote from Jesus in John 10: "The Scripture cannot be broken".
Still not clear? OK, back to Matthew for chapter 15 where Jesus says the Scripture is "the commandment of God".
And one last bit to make it crystal clear, Matthew 5 again, where Jesus says ""Do not think that I came to abolish the Law or the Prophets; I did not come to abolish but to fulfill".
Perhaps instead of ranting about the ungodliness of other people you would do well to read the words of your supposed Lord and saviour.