Love of fate is not (resentful) submission to our fate, i.e.fatalism; it is (joyful) struggle with our fate.
The locus classicus:
1. The Gay Science: With a Prelude in Rhymes and an Appendix of Songs, trans. Walter Kaufmann (Vintage, 1974).
2. The Gay Science: With a Prelude in German Rhymes and an Appendix of Songs, trans. Josefine Nauckhoff and Adrian Del Caro (CUP, 2001) 157:
Bear in mind: for N., “beautiful” means “aesthetic,” i.e. justifiable when seen right, i.e., able to be contextualised and affirmed.
A letter to Overbeck: “—For that matter, I am of a fatalistic ‘godgivenness’—I call it amor fati—” (KSB 6, 199f. ).
“In order to endure it (i.e., the conception which is expressed in the formula ego fatum [“I, fate” or “I, something fated”]) and to not be an optimist, one has to push aside ‘good’ and ‘evil.’ [. . .] the highest good and evil coincide” (KSA 11, 27  ).
“As my inmost nature teaches me, whatever is necessary—as seen from the heights and in the sense of a great economy—is also the useful par excellence: one should not only bear it, one should love it. Amor fati: that is my inmost nature” (“Epilogue,” Nietzsche Contra Wagner  §1):
He continues: “out of such long and dangerous exercises of self-mastery one emerges as a different person, with a few more question marks—above all, with the will to question more persistently, more deeply, severely, harshly, evilly, and quietly than has ever been questioned on this earth before. The trust in life is gone; life itself has become a problem. Yet . . . [e]ven the love of life is still possible—only, one loves differently.” So, does this mean N. is a post-Christian, i.e. one who has transcended Christian ressentiment?
“Such an experimental philosophy . . . wants to break through to the opposite [of negation]—to the point of a Dionysian affirmation of the world as it is, from which nothing has been subtracted, eliminated or selected—it wants eternal circular process. . . . The highest state a philosopher can reach: to adopt a Dionysian stance toward existence—my formula for this is amor fati” (WP 1041 ):
“My formula for greatness in a human being is amor fati: that one wants nothing to be different, not forward, not backward, not in all eternity. Not merely bear what is necessary, still less conceal it—all idealism is mendaciousness in the face of what is necessary—but love it” (“Why I Am So Clever,” Ecce Homo, 2, §10 ).
The Gay Science §277 & 318
“On the Adder’s Bite” Thus Spoke Zarathustra