Though both Italian and Dutch Baroque art often dealt with religious themes, they dealt with them in different ways, in accord with the theological worldviews of, respectively, Catholicism and Protestantism.
Many works of the Italian Baroque were commissioned by Popes, cardinals, and other powerful clerics, who wanted to use art as a way of enhancing the status of the Church as a cultural powerhouse, especially in the wake of the Protestant reformation. These men also wanted to boost their own reputations as patrons of the arts.
The lavish style of the Italian Baroque lent itself to the use of art as propaganda. Baroque artists in Italy deliberately made their works as elaborate as possible in an attempt to project the power of the Roman Catholic Church to a population that was still overwhelming illiterate and therefore susceptible to being impressed by powerful images. These paintings often conveyed a religious and political message as well as a biblical narrative to the illiterate masses who were not able to read the bible themselves.
The Dutch Baroque, in contrast, painted religious scenes that often expressed the overriding importance of the Bible in Protestantism. For Protestants, the Bible was the undisputed word of God, the sole repository of truth. And some Dutch artists of the Baroque sought to illustrate this veneration of Holy Scripture by painting scenes from the Bible in the hope of edifying the masses.
Generally speaking, however, religious themes were much less prominent in the Dutch Baroque than in its Italian counterpart. This was mainly because of the growing secularization of Dutch society that followed from the Reformation. Without the Catholic Church as a patron, the void for patronage was filled by prosperous tradesmen and merchants who invariably wanted portraits of themselves and their families as a way of enhancing their social status, to show that they'd arrived in society.
Nevertheless, such bourgeois were overwhelmingly righteous Protestants, and as well as adorning the walls of their houses with self and family portraits, they also covered them with suitably edifying scenes from the Bible.