“Heaven” is only religious to those who perceive it as such. If you don’t believe in God, or an afterlife, then the word “heaven” is meaningless. Heaven is a word that is used in many ways throughout the world. It does not belong to a particular religion.
“I’m in heaven over my recent marriage proposal”...
“That fudge is heavenly”...
“The vacation we took in the Galapagos Islands was heaven”...
Etc...
And, of course, one of my favorite ice cream flavors: Heavenly Hash.
Hmmm. Haven’t seen it around lately.
You expressed (very well IMHO) what I was thinking.
Webster’s dictionary:
Heaven - the expanse of space that seems to be over the earth like a dome. 2. the dwelling place of the Deity and the joyful abode of the blessed dead. 3. a spiritual state
of everlasting communion with God. 4. a place or condition
of utmost happiness