According to Buddhas final vehicle - Highest Yoga Tantra, the nirvana/liberation explained in Sutra is not actual liberation because emptiness is realized with a gross mind and the gross mind ceases at the time of death. The realizations of tranquil abiding and superior seeing aspects of the gross mind, even though they are powerful. Actual nirvana/liberation is a direct realization of emptiness with the very subtle mind of clear light. This is explained in various Tantras and in the commentaries and teachings of the lineage Gurus.
Therefore, Sutra practitioners must eventually enter the final vehicle to achieve actual liberation. Our fortune to be able to practice Highest Yoga Tantra is thousands of times rarer than achieving a precious human life which itself is already likened to the rarity of a piece of dry rice sticking to a wall when we've thrown a handful at it. If we constantly impute that we are not qualified and insist on following the long strict path (whose time has passed), we may miss an extremely important opportunity. Then, when we happen to eventually be a bodhisattva in a pure land, we'll remember in the distant past we had the opportunity and we'll kick ourself. It is said that bodhisattvas in pure lands other than Keajra (Kechara) pray to be reborn in the human realm with the conditions to practice Highest Yoga Tantra(hyt). If we truly appreciated how horrifying our samsara is and the real danger we're in, we would consider receiving a hyt initiation sooner than later. I know a special situation where a highly realized Yogi had a conversation with someone who was concerned about not being properly prepared to practice hyt. The Siddha explained that if one can keep the most basic commitment of reciting the 4-line prayer of 6 session Guru Yoga 6 times a day (even all 6 times in less than 2 minutes), and keep a mantra commitment (even promising to recite 1 mantra a day) for the rest of their life, they are a suitable vessel to receive the initiation. By receiving the initiation, the door is opened for them to practice more deeply in time, and that even the most concise Yidam sadhanas contain the entire lamrim practice within them. If we committed to the 3 Jewels, then receiving hyt empowerment gives us the opportunity to begin planting seeds and ripening imprints. Meanwhile, we also meditate on lamrim and lojong and perhaps work on various ngondro practices. If we were to wait to get an empowerment until we have completed ngondro, and achieved powerful realizations of lamrim, most of us would never be qualified in this lifetime. If the time for strict requirements for "qualified" disciples was not passed, Geshe Kelsang Gyatso Rinpoche and other Lamas would not be giving hyt empowerment so openly. It is not only because time is running out, but many people have powerful imprints of practicing hyt in the past that are ready to ripen. Fascination and strong interest in Tantric Yidams does not arise from nothing! It comes from our previous tendencies. So now is the time.
If you wanna discuss the traditional strict approach and the dangers of getting initiation early, I'm happy to discuss this further.
