Though most find it a virtue, yet God sees nothing special in loving only those who love us. That's because even pagans and sinners do that. In fact, it is naturally seen in animals, when it takes care of its offspring.
Being a TRUE Christian is more than saying we love God. Here is a test that NOT everyone can pass: In Matthews 5:43-48, it is written:
"You have heard that it was said, ‘Love your neighbor and hate your enemy.’ But I tell you, love your enemies and pray for those who persecute you, that you may be children of your Father in heaven. He causes his sun to rise on the evil and the good, and sends rain on the righteous and the unrighteous. If you love those who love you, what reward will you get? Are not even the tax collectors doing that? And if you greet only your own people, what are you doing more than others? Do not even pagans do that? Be perfect, therefore, as your heavenly Father is perfect".