To Christians bewildered by this agnostic generation

I once heard a magnificent talk given by Bishop Robert Baron where he points out the irresistible power of the Church, promised by Jesus at Caesarea Philippi: "and the gates of Hades will not prevail against it." And Bishop Baron points out that gates do not attack, so this is not about the Church being impregnable, but rather it is the Church that marches onward, and the gates of Hades must give way.

How much marching have we been doing, each of us, in or families, in our parishes and schools, in society? For me, not much.

From Haggai 1:1-2:9

The Lord of Hosts says this: Reflect carefully how things have gone for you. The abundance you expected proved to be little. When you brought the harvest in, my breath spoilt it. And why? – it is the Lord of Hosts who speaks. Because while my House lies in ruins you are busy with your own, each one of you.

Utter destruction of one's enemies - by loving them

Keeping in mind that love does not refer here to an emotion, but an active will to the good of the other, Christian charity (caritas, love, aggape) becomes they most potent form of destroying one's enemies by making them enemies no more. This is in keeping with how Christ exceedingly fulfills the old Law in every way, and God's way is not our way.

From dailygospel.org:

Saint Hilary (c.315-367), Bishop of Poitiers, Doctor of the Church 
On Matthew, IV, 27 

“Be perfect as your heavenly Father is perfect”

“You have learnt what is said: Love your neighbor and hate your enemy…” In fact the Law required love of neighbor but allowed freedom to hate one’s enemy. Faith demands that we love our enemies. By means of a universal feeling of charity it breaks the movements of violence in man’s spirit, not just by restraining its vengeful anger but even more by pacifying it to the point of making us love those in the wrong. To love those who love you belongs to the pagan and we all have an affection for those who show it to us themselves. So Christ is calling us to live as children of God and imitate Him who, through the coming of his Christ, gives sun and rain to the good and the guilty alike in the sacraments of baptism and the Spirit. In this way he forms us according to the perfect life by means of this bond of kindness to all by calling us to imitate a heavenly Father who is perfect.