What was the point of Eva-01's crucifiction ritual in End of Evangelion?

I just remembered that scene from End of Evangelion where all the the Mass Produced Evas lifted Eva-01 in the sky and basically crucified it and formed the Tree of Life around it and performed some kind of ritual, which granted it godlike powers allowing Eva-01 to pull back the Spear of Longinus from the moon. Soon after that the Third Impact started.

Now, as far as I understand, the Impacts are a result of the contact between Adam (or its offsprings) and Lilith (or its offsprings). Gendo got Adam grafted to his hand, and contacted Rei, who has Lilith's soul in her. She took Adam and merged with Lilith's body, thus completing the full contact between Adam's body and soul, and Lilith's body and soul and forming the Giant Rei, which begins instrumentality.

Now, since the Third Impact was basically just because of Giant Rei's decision, what was the point of MP Evas crucifying Eva-01?

I might be wrong somewhere so please correct me.