TMZ/Getty Composite

Olivia Newton-John's Heartfelt Tribute from Husband

Olivia Newton-John's husband, John Easterling, is reeling from the loss of his wife, but finding strength to post some beautiful words in the wake of her death.

John use Olivia's official Instagram account Wednesday to share a message, "Our love for each other transcends our understanding. Every day we expressed our gratitude for this love that could be so deep, so real, so natural. We never had to ‘work’ on it. We were in awe of this great mystery and accepted the experience of our love as past, present and forever."

He went on to call her a healer and the most courageous woman he's ever known ... "It is only the grace of God that has allowed me to share the depth and passion of her being for so long. In her most difficult times she always had the spirit, the humor, and the will power to move things into the light."

He continued, "Even now as her soul soars, the pain and holes in my heart are healed with the joy of her love and the light that shines forward" ... and thanked folks for their love and support.

As we reported, Olivia died peacefully Monday, surrounded by family and friends at her ranch in Southern California. The star battled breast cancer off and on starting in the 90s ... and a source close to Olivia tells us the cancer was the cause of her death.

Olivia and John Easterling, who is the founder of Amazon Herb Co., got married back in 2008.

Click here for info about our online advertising practices.