Swamiji on Non Attachment

You who have read the Gitâ see all through the book that the one
idea is non-attachment. Remain unattached. The heart's love is due to only
One. To whom? To Him who never changeth. Who is that One? It is God. Do not
make the mistake of giving the heart to anything that is changing, because
that is misery. You may give it to a man; but if he dies, misery is the
result. You may give it to a friend, but he may tomorrow become your enemy.
If you give it to your husband, he may one day quarrel with you. You may
give it to your wife, and she may die the day after tomorrow. Now, this is
the way the world is going on. So says Krishna in the Gita: The Lord is the
only One who never changes. His love never fails. Wherever we are and
whatever we do, He is ever and ever the same merciful, the same loving
heart. He never changes, He is never angry, whatever we do. How can God be
angry with us? Your babe does many mischievous things: are you angry with
that babe? Does not God know what we are going to be? He knows we are all
going to be perfect, sooner or later. He has patience, infinite patience. We
must love Him, and everyone that lives — only in and through Him. This is
the keynote. You must love the wife, but not for the wife's sake. "Never, O
Beloved, is the husband loved on account of the husband, but because the
Lord is in the husband."

- Volume 4/Lectures and Discourses/The Great Teachers of the World