The Gemara (Yoma 38.) says:
"Nikanor sailed to Alexandria, Egypt, to bring copper doors [for the eastern gate of the Beis HaMikdash's courtyard]. During his return trip, a storm threatened to drown them. People took one of the doors and threw it into the sea, but the ship still threatened to capsize. They wanted to throw the other door into the water, but Nikanor stood up, wrapped his arms around it, and said, 'If you will throw this door into the sea, throw me in with it.' Immediately, the sea calmed down.
Nikanor was upset that one door was thrown into the sea. However, when they docked at Acco, Eretz Yisrael, he saw that lo and behold, the other door was there, bobbing up and down beside the ship."
Obviously, the Beis HaMikdash couldn't use one door without the other. So why was Nikanor moser nefesh to bring only one door to the Beis HaMikdash? The answer is that he did what he could, and then Hashem helped him.
When my father was a child, he and all of his brothers and sisters would prepare water near their beds so they could wash negel vasser upon awakening in the morning. One evening, there was no running water, so the children went to sleep without preparing water near their beds. In the morning, my grandfather (Rebbe Moshe Mordechai of Lelov zt'l) admonished them, "You should have at least placed empty cups near your bed."
A person must do whatever he can, and Hashem will help him do the rest. Similarly, in regard to praying for Moshiach, each person should feel responsible and do what he can. And then Hashem will help us succeed.
