Musar for Sanhedrin 75:24

The answer to him is near [his question], as we learned: "Thus man was created alone, so that each person should say: 'for my sake the world was created' " (Sanhedrin 37a). Already it brings gratification to G-d, that His children desire and pray for this. And even though their request may not be fulfilled, because the proper time has not yet come or for some other reason, nevertheless, they have done their part and the Holy One, blessed be He, rejoices in this.