Why Are We Not In Pure Land Yet (And How To Ensure We Will Reach It)
If [there] are [sentient] beings
who hear this [teaching,
they] should aspire [or vow
to be] born in that [Pure] Land.
– Śākyamuni Buddha
(Sūtra [In Which The] Buddha Speaks [Of] Amitā[bha Buddha])
According to Amitābha Buddha’s (Āmítuófó: 阿弥陀佛) ’18th Vow [Of] All Born [In] My Land [With] Ten Mindful Thoughts’ (第十八十念皆生我国愿) in the Sūtra [In Which The] Buddha Speaks [Of] Immeasurable Life [Buddha] 《佛说无量寿经》:
If I attain Buddhahood, [if the] ten directions’ sentient beings, [with] utmost sincere hearts [or minds of] joyful faith, desire birth [in] my land, even with ten mindful thoughts, should not [be] born [there, I shall] not attain right awakening.
Only excluded [are those who with the] Five Heinous [Transgressions, who] slandered [the] right Dharma.
Essentially, this means that if anyone is able to express profound Faith (深信) and sincere Aspiration (切愿) to be born in Āmítuófó’s Pure Land with true Practice (实行) of mindfulness of his name, it will be reached. This so since Āmítuófó has already realised Buddhahood, with this vow fully functioning. Even those who had done great evil and/or slandered the Pure Land teachings can reach it if they repent, and give rise to the Three Provisions (三资粮) of Faith, Aspiration and Practice (信愿行) in time.
Since most who consider themselves to be Pure Land Buddhists should already have the Three Provisions, why then, have they yet to reach Pure Land? This would depend on the extent of these provisions. Is Faith profound enough, to be unshakeable? Is Aspiration sincere enough, to be unwavering? Is Practice that expresses Faith and Aspiration true enough, to be genuine?
As many proper Pure Land Buddhists do have Niànfó (念佛) Practice of mindfulness of the name of Āmítuófó in everyday life, which already continually expresses their Faith and Aspiration beyond ten mindful thoughts, why are they not in Pure Land yet? Indeed, there must be Faith and Aspiration, or there would be no Practice at all, what more lifelong Practice. Still, the question of why they have yet to reach Pure Land remains. The answer is in two easily overlooked lines in the Sūtra [In Which The] Buddha Speaks [Of] Amitā[bha Buddha]《佛说阿弥陀经》:
… if [there] are those [who]  already aspired [or vowed],  now aspire [or vow], [or]  will aspire [or vow, with the] desire [to be] born [in] Amitā[bha] Buddha’s land, all [of them will] attain non-retrogression for [progress towards] Anuttarā Samyak Saṃbodhi [i.e. Buddhahood].
In that land, [they have]  already [been] born,  or [are] now [being] born,  or will [be] born.
This is why… all good men [and] good women, if [they] have faith, should aspire [or vow to be] born [in] that land.
(Note that although the word ‘Aspiration’ is commonly used for ‘愿’, ‘Vow’ is a stronger and more appropriate word to use in translation, for representing its very firm nature.)
To further explain what Śākyamuni Buddha meant above, there are three kinds of beings born in Āmítuófó’s Pure Land in terms of time –  those in the past, who already aspired to reach it, have already been born there,  those in the present, who now aspire to reach it, are now being born there, and  those in the future, who will aspire to reach it, will be born there. This is why those with Faith should aspire to reach it – as without Aspiration, it cannot be reached.
The above emphasises that the pivotal factor deciding when Pure Land is reached is the strength of the central provision of Aspiration. It is central because just as sincere Aspiration arises only when there is profound Faith, with sincere Aspiration will there be its expression as true Practice to ensure reach of Pure Land.
Since many Pure Land Buddhists must have aspired to reach Pure Land in the past, within this life, when learning about the Pure Land teachings, why are they not already born there? Again, the pivotal factor is Aspiration. When the Buddha spoke of  those in the past, who already aspired to reach Pure Land having already reached it, he was referring to those who sincerely aspired to do so back then.
If we are to, as  those in the present, most sincerely aspire to reach Pure Land now, we will therefore most sincerely do the Practice needed now, to reach it now. This is while, for many practitioners now, they are of those in the future (within  this present life or  a future life), who will sincerely aspire to reach Pure Land then, when they are the most sincere, perhaps when very old, sick and dying, clearly knowing they have no other choice or better Aspiration. Such Aspiration is ultimate in nature, being the fullest sense of what the Pure Land Tradition’s 9th Patriarch Great Master Ǒuyì (净土宗九祖藕益大师) taught in Spirit Peak [School’s] Essential Treatise (灵峰宗论):
… [L]oathe [the] suffering of birth [and] death [in this] Sahā [World], rejoice [in and] yearn [for the] bliss of enlightenment [in Āmítuófó’s] Pure Land… Furthermore, without [a] second ambition, this [is] named Aspiration.
For most practitioners, giving rise to the above Aspiration when about to depart is the ultimate practice of thought transformation in their lives. This is when prior attachment to this Sahā World transforms to be the most strong and clear revulsion for its repetitive suffering of birth, ageing, sickness and dying, wanting to depart from it (厌离娑婆). Simultaneously, it is when remaining ambivalence towards the Land Of Ultimate Bliss transforms to be the most sincere and joyful Aspiration to seek birth there (欣求极乐). With the push factor of revulsion aligned in the same direction as the pull factor of rejoice, sincere Aspiration is most greatly empowered.
It is not that most practitioners are not sincere at all in their Practice now, leading them to not be in Pure Land now, but that most practitioners are the most sincere when about to depart. In the mean time, we should do our best to keep learning and practising the Pure Land teachings as sincerely and diligently as we can, so as to nurture, accumulate and fortify the Three Provisions for reaching Pure Land in good time. Pivoting especially upon Aspiration to reach Pure Land in the moment, when these provisions are adequate, Āmítuófó will definitely be mindful of this. This is when our Aspiration to reach his Pure Land is fully aligned with his Aspiration to guide us there.
Attaining birth [in Āmítuófó’s Pure Land] or not, completely depends [on] Faith [and] Aspiration [being] present [or] absent.
[The] grade [of] birth [being] high [or] low, completely depends [on the Practice of] upholding [mindfulness of the] name [of Āmítuófó being] deep [or] shallow.
– Pure Land Tradition’s 9th Patriarch Great Master Ǒuyì
(Essential Explanation [Of The] Sūtra [In Which The] Buddha Speaks [Of] Amitā[bha Buddha])
The Three Provisions 三资粮
The Principle Of ‘Vow Now For Birth Now’ 今发愿今往生的原理
The Path To Non-Retrogression Starts Now
How To Transcend Your Present Suffering Now
Namo Amituofo: Translation by Shen Shi’an