माया

Maya is, in the Gita, the divine power that belongs to the Lord. In chapter 7 he says that this divine illusory energy of his, made of the three modes of nature, is very hard to cross, but those who take refuge in him alone cross it (Gita 7.14). One effect of this power is that knowledge is covered. The next verse says that those whose knowledge the illusory energy has carried off, and who hold to a proud bent of mind, do not turn to him (Gita 7.15).

In plain terms, maya is the pull that works in our daily moods, cravings and restlessness, and that gives us the feeling that we can manage everything alone. That feeling is what the Gita calls delusion.

Common misreading: that maya means the world is false, or that it is an evil power separate from the Lord.

Better sense: the verse calls it "mine" and "divine". It is his own power, so the remedy is with him as well. That is why the Gita names refuge as the way across (Gita 7.14), and refuge does not mean giving up work (Gita 3.30).

To read the whole topic, see The Illusory Energy and Surrender.