Can stative verbs be used as gerunds?

If the present participle continuous form is not used for stative verbs then why do we sometimes see stative verbs as gerunds, such asloving, believing, knowing, hating, being, etc.?

For example:

Loving my children is not just my duty as a parent, it is inherent in my very being.

When I googled, I found the book Reference to Abstract Objects in Discourse by Nicholas Asher which says "No stative verbs have gerund forms" so I was totally confused: are stative verbs used as gerunds or not?

Stative verbs are used in the gerund form as second verbs, not in continuous tenses.

I love knowing that I've helped someone understand a point in English.

When two verbs are together, depending on the first verb, the second verb might be in the full or bare infinitive, a gerund, or to + gerund.

I want to believe it's true.

Let me believe in you, if no one else will.

I love knowing I've helped someone.

I look forward to understanding computers better, with your help.

Stative verbs as gerunds can start a sentence.

Believing in yourself is necessary to succeed in life.

From the source http://www.myenglishteacher.net/gerunds.html :

"Even stative verbs (those verbs that almost never have -ing) can be turned into gerunds. A native speaker of English would NEVER say I am believing you. However, a native speaker could say"

"Believing in God is important."

"Believing, here, is a gerund. It is NOT a verb. Believing in God is a gerund phrase."

http://www.myenglishteacher.net/gerunds.html

To qualify the source, because of a comment made, being a native speaker of English is no guarantee that the language will be used correctly. The obvious implication of the statement in the quote is a native speaker who speaks educated English.

Note: Some so-called stative verbs can be used in a continuous tense, but with a different meaning. For example: I see you now. I'm seeing the doctor tomorrow.