Spike doesn't believe in destiny. He scoffs at anyone who tries to tell him that he was fated all along to fall in love with a Slayer and fight for his soul so he'd be worthy of her.
These were choices he made. He chose to love her, unnatural as it was. He chose to win his soul for her. Then he chose to die to save the world. The last was partly selfish. He had no desire to let Angel get the glory again.
Choices not destiny. He'll go to his grave a third time believing that.
He's love's bitch; he fully admits that.
He refuses to be fate's bitch as well.
End