Is it true? No.

If it were, how could one be a Christian at all if not by following Jesus teachings?

Jesus said, “If you hold to my teaching, you are really my disciples. Then you will know the truth, and the truth will set you free.” John 8:31,32

If Jesus’ teachings don’t apply to us, then we can’t be his disciples—Christians, or know the truth and be set free by it. How sad and empty that would be!

Yes, a few things Jesus said were specific to the situation but the truth is, we are to follow Jesus’ teachings in order to be his disciples, which results in knowing the Truth and in freedom..