In the world of the future, when the paths of the sutras [to enlightenment] are destroyed and ended, I, with loving-kindness, compassion and empathy, will specially retain this sutra [on Amitabha Buddha’s Pure Land teachings], to dwell for one hundred years [longer]. If there are such beings, who encounter this sutra, they can, as they wish, according to their aspirations, all attain deliverance.
– Sakyamuni Buddha
(Immeasurable Life Sutra)
Are Buddhists encouraged to ‘aspire’ to return to the rounds of rebirth, to look for their past Dharma teacher(s)? No, especially if such teachers are already deceased, and with no clear signs that they are already enlightened, to have consciously manifested rebirth back in Samsara. Without indisputable signs, these teachers are likely to still be unenlightened, having forgotten about their own past lives too, including any spiritual aspiration to seek their students. If even beginner Bodhisattvas will forget their past lives, how can teachers ‘missing in action’ save anyone?
It is also true the other way round – that students, who are even spiritually weaker, will be even further from enlightenment, and more forgetful about their past lives, including any spiritual aspiration to seek their teachers. We can be certain that we will not recall this life in the next, just as we cannot even recall our surname in our immediate past lives, that we were ‘so used to’! We cannot even recall what we had for lunch three days ago! It is thus sheer deluded idealisation, that unenlightened teachers and students can stay united in the rounds of samsaric rebirth life after life.
It is spiritually dangerous to have misplaced confidence by projecting the messiah complex upon any absent teacher. We should instead obey all Buddhas’ collective instructions to aspire to reach Amitabha Buddha’s (Amituofo) Pure Land – where we will be fully empowered to recollect all our past lives, and have the best teacher possible – Amituofo! It is the optimum place, as the Amitabha Sutra teaches, ‘to be able to, with all such beings (i.e. great Bodhisattvas and Arhats) of superior goodness, meet together in one place.’ (得与如是诸上善人，俱会一处。) All should gather there!
While all the precious Dharma learnt will be forgotten if Pure Land is not reached, there is at best some merits from Dharma learning and practice brought over to the next life. However, with only merits and no wisdom recollected, the terrifying existential problem of three lifetimes will repeat indefinitely. Briefly, it relates to how merits accumulated in this life  leads to a better future worldly life , which creates spiritual complacency, that goes against the Dharma. By life , the merits from life  would have depleted, while the negative karma from life  bears fruit as suffering! Reaching Pure Land ends distracting worldly life instead; while spirituality only advances.
It is thus wise to follow the clear and excellent examples of great Bodhisattvas (such as Manjusri Bodhisattva) and great masters (such as Lama Tsongkhapa), instead of ‘following’ a missing teacher. (Note that Lama Tsongkhapa is believed to be manifested from Manjusri Bodhisattva, both of whom had written Aspiration Verses to personally reach Amtuofo’s Pure Land.) Mara, however, will distract the masses from the Pure Land path, to delay their Buddhahood, while they sink ever deeper into this Dharma Ending Age. Even if not Mara himself at work, the ill effects are still as above!
Even though every single Buddha and great Bodhisattva already vowed to guide all beings to Buddhahood, they still offer clear instructions to reach Amituofo’s Pure Land, which is the swiftest Dharma school for non-backsliding progress towards Buddhahood. At no point do they urge ordinary beings like us to simply return to Samsara in this Dharma Ending Age, to await for them or some unseen guru-saviour – as this is the least efficient place and era for steady Dharma learning and practice. Remember – even with much merits (福德) but without applied wisdom (智慧) of the Pure Land teachings, this will lead to depletion of merits and loss of wisdom. – DharmaProtectors
In the Dharma Ending Age, when 100 million of 100 million people practise the Dharma, it is rare that one will realise the way; only depending on mindfulness of Buddha, [is it] attainable, liberation from [the cycle of] life and death.
– Sakyamuni Buddha
Are You ‘Recycling’ Yourself Every Three Lifetimes?
Should I Return To This World To Find My Teacher?
Where Best To Go When This Life Ends?
Is Our World Becoming A Pure Land Soon?
How Death Hinders Progress To Liberation
Prayer To Be Born In The Land Of Bliss By Je Tsongkhapa
Manjusri Bodhisattva’s Verses Of Aspiration For Birth In Pure Land
How Manjusri Bodhisattva Urged Pure Land Practice In This Era
Do Pure Land Aspirants Forsake Others?
The Buddha’s Admonition Against False Spiritual Claims
What If You Are A ‘Tulku’ (Recognised Reborn Master)?