We should never feel obligated to keep negative people close to us when all they do is affect our own being. However, those of us who have the it of life within us are not called to keep it to ourselves. That would be nothing but selfish paranoia and the perversion of power. I believe that we the few - the thinkers, the movers, the shakers, the believers, the lovers - are called to more than simply surrounding ourselves with positive people. We are called to reciprocate that positivity tenfold onto those in our circles that thrive on negativity, because reality is that they aren't really thriving anyway, just surviving. What you believe faithwise is irrelevant - all powerful people should find it their number one priority to empower others to discover that same strength. Since we all love lovely quotes, here's one: "We are all meant to shine as children do. We were born to make manifest the glory that is within us. It's not just in some of us; it's in everyone. And when we let our own light shine, we unconsciously give other people permission to do the same. As we are liberated from our fear, our presence automatically liberates others."
So yeah, you can do what you want in regards to the relationships that make or break your social consciousness. But if you fully intend on being a person who gives until it hurts, sometimes sacrifice is the appropriate alternative to pride.