As an amateur student of comparative religion, I see a striking point of convergence and one of divergence between the three Abrahamic religions (Judaism, Christianity and Islam) on the one side, and Hinduism on the other.
The Abrahamic religions may have their internal differences, but they agree on one point. They all worship the "God of Abraham", who is invisible, formless, all-pervasive, all-knowing and all-powerful.
From their perspective, Hinduism is the polar opposite, because it is polytheistic and idolatrous. These acts are considered grave sins in their philosophy.
However, it may surprise many people belonging to the Abrahamic religions to know that Hinduism too has the concept of an invisible, formless, all-pervasive, all-knowing and all-powerful entity called Brahman (pronounced bruh-muhn, and not to be confused with either the Creator deity (Brahma) of the cosmic creator-preserver-destroyer trinity, or the priestly caste of brahmans (pronounced braa-muhN)).
There is a tiny difference in the way Hinduism and the Abrahamic religions view this formless entity. Hinduism ascribes no gender to the Brahman, while the Abrahamic ones are emphatic that the God of Abraham is a "He".
Setting aside that one difference, there is a surprising convergence in the two theological schools, i.e., that there is one invisible, formless, all-pervasive, all-knowing and all-powerful entity that is responsible for all of Creation.
Now comes the difference between the two theological schools.
The Abrahamic schools consider the worship of any deity other than this formless one as a grave sin. Any other deity is considered a "false god", or worse, a creation of the Devil meant to lead humans astray. Worship of idols is also considered a grave sin.
These are the very first two commandments of the ten enshrined in Judaism and Christianity.
"Thou shalt have no other gods before me"
"Thou shalt not make unto thee any graven image"
These rules seem consistent with the view that God is formless.
How then does Hinduism reconcile the two concepts of a single formless being and the worship of multiple deities and idols?
Simple. Hinduism considers these practices to be harmless, not sins.
Hindu philosophy says that any prayer directed at any deity or idol ultimately finds its way to the supreme consciousness or Brahman. Hence, although these deities and idols are not the Brahman, they are just aids to make an abstract concept more concrete for ordinary people.
To take an analogy from computing, all programs are ultimately ones and zeroes. However, it's hard for programmers to code in ones and zeroes, so they code in "higher-level languages" that are more understandable, and compilers then convert these programs into ones and zeroes. All IT professionals know that what computers execute is a sequence of ones and zeroes, but they also accept that coding in a higher-level language is not a grave sin, but a welcome aid.
So that's the core point on which the Abrahamic religions and Hinduism agree - that there is only one formless entity that has created the Universe.
And the core point on which the two schools disagree is whether the worship of other deities and idols is a grave sin, or just a harmless and indeed useful aid to make the abstract more concrete for those who wish to pray.
This is an example of what can only be seen in a Hindu context - an image containing Muslim, Hindu and Christian icons in one. This would be anathema to Muslims and Christians, but is acceptable to the Hindu philosophy. It's all Brahman behind the images, anyway.
As an IT professional (not as a former Hindu!), I find the approach of Hinduism pragmatic, while the approach of the Abrahamic religions seems needlessly harsh.
A related post is about the parallels between the Abrahamic religions and Hinduism's Dvaita school: "An Indian Contribution To Philosophy"
