The scribes and Pharisees also showed their hypocrisy in a series of ways, which Christ now draws attention to. First, they refused to enter the kingdom of heaven themselves.
Suppose there is some new initiative that certain people in a local church would like to start. It is not something unbiblical, but something the church ought to have been doing, but has failed to do until now. Certain individuals have had it laid on their hearts that they should commit themselves to this new work and they are willing to make the sacrifice to do it, but there are other more long-standing people in the church who have never done this thing, and not only will they not be persuaded to start doing it, but they want to block others from doing what they have failed to do. It might be the start of an evangelistic Sunday School, or the visitation of the neighbourhood. It will involve hard work. But if others begin this work, it will show up these more long-standing members, so they block it, using what authority they have.