Likutei Moharan 52:2/ליקוטי מוהר"ן נ״ב:ב׳

12. Now the main intention behind His creating the entire world for Israel was so that Israel should carry out His will, and so that they should return and cleave to their Source—i.e., that they should return and be encompassed in God, Who is a necessary reality. It was for this that everything was created.

2We see then that whenever Israel does the will of the Omnipresent and is enveloped in its Source, Who is a necessary reality, through this the entire world, which was created for them, is encompassed in necessary reality. This is the primary purpose for which the world was created. And only because of this is God obligated, so to speak, to create and maintain all the worlds for Israel; so that they should carry out His will, as explained above.

3And so it is specifically then, when they carry out His will, that the world is encompassed in the aspect of necessity reality. For the more they carry out His will, the more they are encompassed, together with all the worlds that are dependent upon them, in necessary reality. For by doing His will they return and are encompassed in Him, He being a necessary reality, and so all the worlds that are dependent upon their souls are encompassed together with them in necessary reality, as explained above.