A friend once explained to me why his (non-denominational) pastor didn't talk much about sin and evil: one should just talk about the "good news" of the Gospels, not the "bad news" of evil, lest one become fascinated, even fixated, on the latter.
Quite aside from the danger of making a kind of "happy talk" Christianity, it just isn't honest to ignore evil. To do so gives an incomplete picture of the world, and begs the question of what we needed to be saved from in the first place. There is good in the world, and there is evil. Deal with both.
Anyone who has ever successfully tended a garden knows about celebrating Good while confronting Evil. How's that? Well, what happens if you just plant nice flowers in your garden, but never pull any weeds? The weeds take over. What happens if you weed like mad but never plant any flowers? You get a barren patch of ground. But if you both weed and plant, then you get a garden.