Like many epic heroes from antiquity and the Middle Ages, Beowulf may strike modern readers as being a violent and above all boastful man. For instance, when he appears before Hrothgar to announce his intention to destroy Grendel, he claims that the "best of my people" advised him to go there because
...they know full well the strength of my might. They themselves were witnesses when I came from battle, flecked with my foes' blood; there I bound five beasts and bested the brood of giants. I slew beasts by night on the waves, avenging at my own peril the Geats, whose woe they sought—I crushed these grim ones. Grendel, this cruel monster, will now be mine to best in single battle!
This boasting, as well as the persistent glorification of gory combat embodied by Beowulf, seems particularly odd and perhaps a bit off-putting alongside his Christian faith. It is important to remember, however, that in the society that produced Beowulf, military leadership and accomplishments were prized as the traits of a good leader. Virtually every medieval epic or history attempts to play up the leading character's martial prowess. Keeping this in mind, modern readers should be able to see that the compilers of Beowulf intended that the title character be noted for his bravery, his loyalty, and his faith. Some characteristics we abhor today were very much admired in early medieval Europe.
This is an interesting question. I do not think that there is a monolithic view about Beowulf. In other words, all people will differ in their views of him.
Some might view Beowulf as a vain war monger, who likes to fight. These would probably be turned off at all the fighting and macho mentality that dominates much of the book.
Others might be turned off to the religious dimension in the epic. Even a cursory reading of the epic will show that fusion of Germanic war culture and Christianity. Many people would see the religious ideology as something distasteful in our era where people kill in the name of religion.
Still others may find Beowulf brave and courageous. The fact that people still read this work says something. In the end, opinions will run the gamut.