My take is rather simplistic.
If you do not take refugees for fear of terrorists hidden in their midst, then you become a target for terrorists because of your closed borders.
If you take refugees, then you may have allowed a few terrorists in that may take advantage of the new freedom and you're a target because you're taking people away from their homelands.
Regardless, we're targets for terrorists and they're going to get here one way or another. If there is a terrorist that does not want to go through screening checks, he'll still find a way into the country.
I think that is a pointless debate.
What I find having greater merit for debate is that the population is up in arms because the federal government is going to spend $25,000,000.00 to bring in 25,000 refugees rather than invest that money on social programs that would benefit those who are current residents. Thing is, that's only $1,000 per refugee. Not a lot of money when put into context.
I think the most profound argument I have heard yet is that the people who emigrate from the poorer countries of the world are those who are actually the most capable of creating change and improving their impoverished nations. As an example, Why is it that doctors from impoverished third world countries are practicing medicine in Canada and the United States whilst doctors from here end up volunteering to go to these third world countries to donate their time. What we are doing is stripping these countries of their best and brightest and preventing them from becoming developed nations.