Spiritual blindness

Right now I live in a house (and extended family) full of unbelievers. My mother and 7 year old grandnephew are probably the best of the lot, as I'm not sure they are unbelievers. My mother just curses like a sailor, but with the way a lot of our family acts, sometimes I want to too. My nephew, however, is different. He lost his mother (my sister) less than three months ago to alcoholism, but he continues down the same path as hard as he can. I tell people sometimes I feel like I live in a consumption ward, because he coughs all the time, yet he keeps smoking. His mother was like this--she spent over half a year in jail for a DUI, got clean of alcohol and tobacco, and on the night she was released she was drinking and smoking. It continually amazes me the level of blindness to the repercussions of their actions these people have, and the deepness of their denial. I know that "whenever anyone turns to the Lord, the veil is taken away" (2 Cor. 3 16), but how hard is it to grasp that your addictions are not only killing you but destroying your family, especially your children?
I tell people sometimes that these people make me feel so smart. I was blessed enough to get in church and with the Lord just as I was hitting puberty. At 14 I got involved with a youth ministry, and when they started their own church about a year later, I went with them, and that's where I still attend. There I got the first Bible I really studied and read, which has been a major theme in my life. I hung around with the youth group in high school. I have never drank or smoked. I have never had sex, having made the True Love Waits pledge around 1994. Thus I broke several trends in my family. Half of my nieces had babies as teenagers. I also completed high school and college, the first in my immediate family to do so. As I look back on my life, the decisions that I have made have been heavily influenced by the Lord and His church, and considering the path my family has followed, I know I have chosen the right path. And I am thankful I did not have to experience all the problems these supposedly fun things have caused them.