The Buddha’s supramundane teachings leading to Nibbana are the highest possible path & human attainment according to Buddhism. Nibbana is the end of greed, hatred & self-delusion. The Dhammapada says:
Dhp 273. Of all the paths the Eightfold Path is the best; of all the truths the Four Noble Truths are the best; of all things passionlessness is the best: of men the Seeing One (the Buddha) is the best.
Dhp 274. This is the only path; there is none other for the purification of insight. Tread this path, and you will bewilder Mara.
I did mention to you previously there are two types of teachings in Buddhism: (i) supramundane, which align with emptiness & anatta (not-self); & (ii) mundane, which are tainted by self-views . Generally, for laypeople, the Suttas say to teach the mundane Path To Heaven. Specifically, DN 31 says:
Ascetics and brahmins served by a gentleman (lay devotee) in these five ways show compassion to him in six ways. They keep him from doing bad. They support him in doing good. They think of him with kindly thoughts. They teach him what he does not know. They clarify what he’s already learned. They explain the path to heaven.
Among the major &/or well-known religions, Christianity comes closest to Buddhism. There are many teachings of Jesus about abandoning greed, lust (celibacy), anger & hatred; and abiding in the unconditional love which Buddhism says in the Path To Heaven (e.g. DN 13). However, to be entirely ‘supramundane’ also requires abandoning the defilement of delusion or ‘self-view’. Christianity is not entirely clear about this. For example, when the Gospels say to give up your life for Jesus sake (Mark 8:35) or to lose your life ( John 12:25), it is unclear whether this is the giving up of self-view or, instead, merely the giving up on your personal self for the sake of a greater Jesus-self. While I have not studied the history of the Gospels, it can be discerned how Mark is the most primitive, then Luke adds to Mark, then Matthew adds even more, including adding Beatitudes & even amending the Jesus teaching of divorce to including adultery as a justification. John’s Gospel is more mystical, referring to the Holy Spirit and how the Father is the Gardener. However, it seems not clear who Jesus was and what he taught. For example, the Letters of Paul rarely mention any Gospel stories & narratives. Language is also problematic. For example, a Buddhist will label the notion of 'Eternal Life" as the wrong view of Eternalism. However, in John as well as in the Gospel of Thomas, the notion of “not experiencing death” occurs. In Buddhism, the literal notion of “Eternal Life” is a wrong view; where as the notion of “The Deathless” is a synonym for Nibbana. In summary, Jesus supposedly only taught for 3 years; where as the Buddha supposedly taught for 45 years. The New Testament is heavily imbued or mixed with what can be called “spiritual language”, that is, linguistic metaphor, such as at John 3:6. For example, obviously Jesus was not preaching cannibalism when he exhorted to eat his body & drink is blood. Thus words such as “death” can mean “spiritual death” rather than “physical death”; a notion also found in Buddhism, such as in Dhp 21. Therefore, when Jesus says charity stores up heavenly reward, often it is unclear exactly what this heaven is, whether after death or in the here & now. Of course Luke comes along with stories such as Lazareth & The Rich Man and Matthew comes along with The Sheep & The Goats.
In summary, the supramundane teachings of Buddhism are about developing the insight that eliminates greed, hatred & delusion from the mind. Delusion is mostly about self-delusion, namely, regarding life as “I”, “me”, “mine” & “self”. While Christianity has abundant teachings about eliminating greed & hatred, it is seems unclear what the Christian position is about the defilement of delusion or self. While Christianity obviously encourages the abandonment of selfishness; it appears there is no literal unambiguous teaching in Christianity about purifying the mind of every trace of self-view. For example, in the EBTs, when a monk was strongly attached to the Buddha as being a ‘self’, the Buddha generally gave a teaching so the deluded monk no longer regarded the Buddha as a ‘self’ or ‘being’. Instead, the Buddha, while fully enlightened in mind, was merely five aggregates, which are impermanent & unsatisfactory (SN 22.85).
Venerable Ānanda said to him, “Even if the Teacher were to decay and perish? Wouldn’t that give rise to sorrow, lamentation, pain, sadness, and distress in you?”
“Even if the Teacher were to decay and perish, that wouldn’t give rise to sorrow, lamentation, pain, sadness, and distress in me. Still, I would think: ‘Alas, the illustrious Teacher, so mighty and powerful, has vanished! If the Buddha was to remain for a long time, that would be for the welfare and happiness of the people, out of compassion for the world, for the benefit, welfare, and happiness of gods and humans.’”
“That must be because Venerable Sāriputta has long ago totally eradicated ego (I-making), possessiveness (mine-making) and the underlying tendency to conceit. So even if the Teacher were to decay and perish, it wouldn’t give rise to sorrow, lamentation, pain, sadness, and distress in him.”
When the Buddha became fully extinguished, some of the mendicants there, with arms raised, falling down like their feet were chopped off, rolling back and forth, lamented: “Too soon the Blessed One has become fully extinguished! Too soon the Holy One has become fully extinguished! Too soon the seer has vanished from the world!” But the mendicants who were free of desire endured, mindful and aware, thinking, “Conditions are impermanent. How could it possibly be otherwise?”