God is love and he who abides in love abides in God and God abides in him.
The soul lives where she loves more than in the body she animates; for she does not live in the body but rather gives life to the body, and lives in the Object of her love.
The soul that loves God lives more in the next life than in this, for the soul lives where it loves more than where it gives life, and thus has little esteem for this temporal life.
It should be known that love never reaches perfection until the lovers are so alike that one is transfigured in the other. And then the love is in full health.
The reason is that in the union and transformation of love each gives possession of self to the other, and each leaves and exchanges self for the other. Thus each one lives in the other and is the other, and both are one in the transformation of love.
In the spiritual marriage the soul thereby becomes divine, becomes God through participation. It is accordingly the highest state attainable in this life.
Extract from the Spiritual Canticle by St John of the Cross