I used to think that the apostates after quitting Islam become enemies to the Muslim brethren.
Most religious zealots have this kind of "us vs. them" mentality.
Is either you are with "us" or you are with "them". There is no spirituality in it. Just politics.
This is exactly why I dislike religions so much. They tend to foster this anti-humanistic stance.
How about being a human being first and foremost? And think of all humanity as if they are your sisters and brothers?