Spiritually speaking, is lack of ambition a bad thing?

No, it's not—

What they speak of is *worldly* ambition.

I have little to no worldly ambition...

Though I do put ambition and momentum—raja—into my spiritual works.

While I do have various relics (say, the two sets of three talismans), as well as many other tools, it is for their aesthetics, symbolism, and utility, rather than out of avarice.

My true happiness comes from pursuits of the mind and spirit.

I no longer have the level of empty longing for the material that so many have.

(((((@Mysterious ❀ @Esmerelda)))))

Like any other stuff even lack of ambition is both good and bad.

Good because your needs are satisfied then why to get greedy and become restless, thus destroying mental peace.

Bad because human life is meant for service to Godhead, but we should not have self centered ambitions but Krishna Centered. Its never bad to have an ambitions to do welfare for humanity.

E.g.: Srila Vyasadeva, the author of the vedas didn't feel spiritually satisfied even after writing all the vedic scriptures so he asked his Spiritual master Sri Narada who advised him to write the Vedanta Sutra aka Srimad Bhagavatam. Thereafter he felt spiritually satisfied.

Well spiritual world is exact opposite to material world , whatever is regarded right is in this exact opposite there , thing which you value in this material world has no value there . all these ambitions, goals , perceptions do's and don'ts right and wrong ,are applicable to only this world , so if you are opposite and difference to all what has said or done in this world then it means you are progressing in spirituality .. that's what lord krishna said in gita that what is night for all beings is time of awakening for spiritual person ..

From where I'm standing, it sounds like your ambition is to justify your lack of ambition. :P

No ambition would... *arguably* be a bad thing. Nothing would ever happen. Like, ever. =p That'd be very depressing.

That doesn't mean that you should deliberately try to be as ambitious as physically possible. Whatever floats your boat.

I have never felt ambitious enough but now I feel like I must move forward to feel spiritually fulfilled in a nurturing sense, because I have failed to protect my heart.

It's only "bad" if one of your goals is to succeed financially in our society. If that's one of your goals, being non-ambitious is a "bad" way to achieve it.

If that's not one of your goals, then whatever. Good luck feeding and clothing yourself.

Yes. There is nothing spiritual about it.

If you can do that and still get the bills paid, more power to you.

Depends.

Is it lacking because you're depressed ?

Or are you just plain lazy ?

depends