In theistic religions, scriptures are either a form of primary revelation - an incorruptible verbatim record of the words of god(s) conveyed by prophets, or a form of secondary revelation - a divinely revealed vision seen by prophetic seers that is conveyed in their own words.
In Buddhism, the scripture mainly contains the discourses and teachings of the Buddha and his chief disciples, as recorded and passed down orally through the monastic order. The teachings of the Buddha are called the Dhamma. It is what he has left behind for his followers to guide them.
The Buddha is seen as the fully enlightened teacher, with an extraordinary ability to teach. He is not viewed as a god or an incarnation of a god. After his passing away, he is not reachable through prayers.
Thus spoke the Venerable Ananda, but the Blessed One answered him,
saying: "What more does the community of bhikkhus expect from me,
Ananda? I have set forth the Dhamma without making any distinction of
esoteric and exoteric doctrine; there is nothing, Ananda, with regard
to the teachings that the Tathagata (Buddha) holds to the last with
the closed fist of a teacher who keeps some things back. ...
"Therefore, Ananda, be islands unto yourselves, refuges unto
yourselves, seeking no external refuge; with the Dhamma as your
island, the Dhamma as your refuge, seeking no other refuge.
DN 16
In Buddhism, the meaning is more important than the phrasing. In fact, to aid memorization of the Pali suttas, similar phrases or verses conveying the same meaning have been altered to become exactly the same, as explained in this answer.
Now, you might think, ‘These two venerables agree on the meaning but
disagree on the phrasing.’ So you should approach whichever mendicant
you think is most amenable and say to them: ‘The venerables agree on
the meaning but disagree on the phrasing. But the venerables should
know that this is how such agreement on the meaning and disagreement
on the phrasing comes to be. But the phrasing is a minor matter.
Please don’t get into a fight about something so minor.’
MN 103
In theistic religions, one is generally expected to have faith and unquestioningly accept the words of god(s) to be true.
In Buddhism, it's ok to question the scriptures.
"Now, Kalamas, don't go by reports, by legends, by traditions, by
scripture, by logical conjecture, by inference, by analogies, by
agreement through pondering views, by probability, or by the thought,
'This contemplative is our teacher.' When you know for yourselves
that, 'These qualities are skillful; these qualities are blameless;
these qualities are praised by the wise; these qualities, when adopted
& carried out, lead to welfare & to happiness' — then you should enter
& remain in them.
Kalama Sutta (AN 3.65)
In Buddhism, the Buddha simply rediscovered the wisdom that was known to previously enlightened ones before him, but have since been forgotten.
Those who were Arahants, Rightly Self-awakened Ones in the past —
they, too, dwelled in dependence on the very Dhamma itself, honoring
and respecting it. Those who will be Arahants, Rightly Self-awakened
Ones in the future — they, too, will dwell in dependence on the very
Dhamma itself, honoring and respecting it. And let the Blessed One,
who is at present the Arahant, the Rightly Self-awakened One, dwell in
dependence on the very Dhamma itself, honoring and respecting it."
SN 6.2
In theistic religions, it's usually not acceptable to consider other religions to be equally true, even if they teach the exact same thing. This is because the identity of the god(s) is more important than the teachings.
In Buddhism, other religions are acceptable to be true if they teach the exact same thing as Buddhism. This is because the teachings are more important than the identity of the teacher.
And the Blessed One spoke, saying: "In whatsoever Dhamma and
Discipline, Subhadda, there is not found the Noble Eightfold Path,
neither is there found a true ascetic of the first, second, third, or
fourth degree of saintliness. But in whatsoever Dhamma and Discipline
there is found the Noble Eightfold Path, there is found a true ascetic
of the first, second, third, and fourth degrees of saintliness. Now in
this Dhamma and Discipline, Subhadda, is found the Noble Eightfold
Path; and in it alone are also found true ascetics of the first,
second, third, and fourth degrees of saintliness. Devoid of true
ascetics are the systems of other teachers. But if, Subhadda, the
bhikkhus live righteously, the world will not be destitute of arahats.
DN 16
With regards to the universal truth of the laws of nature, we find the following statement about the three marks of existence.
“Mendicants, whether Realized Ones arise or not, this law of nature
persists, this regularity of natural principles, this invariance of
natural principles: all conditions are impermanent. A Realized One
understands this and comprehends it, then he explains, teaches,
asserts, establishes, clarifies, analyzes, and reveals it: ‘All
conditions are impermanent.’
Whether Realized Ones arise or not, this law of nature persists, this
regularity of natural principles, this invariance of natural
principles: all conditions are suffering. A Realized One understands
this and comprehends it, then he explains, teaches, asserts,
establishes, clarifies, analyzes, and reveals it: ‘All conditions are
suffering.’
Whether Realized Ones arise or not, this law of nature persists, this
regularity of natural principles, this invariance of natural
principles: all things are not-self. A Realized One understands this
and comprehends it, then he explains, teaches, asserts, establishes,
clarifies, analyzes, and reveals it: ‘All things are not-self.’”
AN 3.136