In a brilliant move to unify the church, Pope Francis approved the canonization of Pope John XXIII and John Paul II. Pope Francis realized that most Catholics like both popes, but some liberal Catholics love John XXIII and think John Paul was too authoritarian. On the other hand, some conservative Catholics love John Paul and think that John XXIII pushed the church into chaos.
With the joint announcement, Pope Francis is saying we do not have to choose between popes; we can honor and revere both as holy men who served the church well in their times.
The pope would agree with St. Paul (1 Corinthians 3:4) who criticized those who said "I belong to Paul," or "I belong to Apollos." "What is Apollos, after all, and what is Paul? Ministers through whom you became believers...for we are God's co-workers." What matters is that we all belong to Christ.
What was most remarkable about the announcement was the decision by Pope Francis to waive the requirement of a second miracle for the canonization of John XXIII. If Francis had not done this, John Paul’s canonization would have moved ahead of his predecessor’s. Pope Francis found this unacceptable.
According to Divinus Perfectionis Magister (The Divine Teacher and Model of Perfection), the church rules for canonizations adopted in 1983, one miracle is required for beatification and a second is required for canonization, except for martyrs who only need one miracle.
Since this is a legal requirement not something based on doctrine, the pope has the right to wave it. In fact, prior to the revision of the rules for canonization in 1983, a number of theologians and experts like Jesuit Fr. Peter Gumpel, argued for eliminating the requirement for any miracles.
Once again, Pope Francis has shown that he is willing to ignore tradition and change the rules to do what he thinks is best for the church.