The Counter-Reformation was introduced to re-claim "lost souls" from the Protestants. Whether the Counter-Reformation can be judged a success depends on a definition of "success". It did give:
1. Greater clarity with regards to doctrine - an unequivocal set of rules.
2. The superstitions of the Medieval Church were under control.
3. New orders were established and went into the community to do "good work" and to help the sick and poor. A spiritual commitment applied to all tasks, which was a good example to lay people.
4. Greater importance put on communion, which enabled the faith to be cultivated and spread.
5. Popes were more open to constructive change and recognised the corruption of the old church. More churches were built.
6. The power of the popes was unquestioned after Trent - this was good if they were pro-reform.
7. The Counter-Reformation proved to the outside world that the Catholic Church had recognised its past failings and was willing to reform itself rather than blind itself to its faults.
8. Ideas of the new Catholic Church spread by groups like the Jesuits.
10. The power of Spain in the C16 meant that the Catholic Church had very strong backing.
Though all failings had not been removed, the Catholic Church was in a much healthier state in 1600.
The Roman Catholic Church existed in Spain, Italy, Spanish Netherlands (at this time), Austria, Bohemia, Hungary Bavaria, Poland, France and various south German states.
However, the states that had adopted Protestantism remained.
If the Counter-Reformation had been introduced to re-claim souls lost to Protestantism in Europe then it failed. However, to balance this, it had gained millions of new followers in the Americas and the Far East as a result of the work done by the Jesuits. Though its geographic extent in Europe had shrunk by 1600, its ability to deliver to those regions it still controlled was good.