I understand. However, we, each of us, represents that Catholic presence that you speak of, and we need to be sensitive to the Holy Spirit as to when and where to share our faith. This means that we all need to function in a constant attitude of prayer so that we can know when we should speak and when we should keep silent.
I agree that there is a lot of hell out there and we are called to stand against it…but remember also what Our Blessed Lord said about not casting our pearls before swine and what will happen if we do.
Matthew 7:6 says*** “Give not that which is holy to dogs; neither cast ye your pearls before swine, lest perhaps they trample them under their feet, and turning upon you, they tear you.” (see also Matthew 10:16)
That is precisely what will happen in many of these cases and that is why I urge caution and discernment. See, some of us, (Myself for instance) have been born into apologetics by a sort of crucible of fire one way or another. For some it was internal, but for me it was external. It is not a path that I recommend to anyone, nor do I treasure that difficult experience that it was, though I recognize that it was the means by which God drew me home to our most holy faith and fed my own internal hunger for the truth.
However, not everyone we encounter, nor every anti-Catholic propagandist is our mission. It is, I believe much more important to help build up Christ’s church by providing Catholics with the answers to such things so that they are not deceived and proselytized away from the faith.