"Belief is almost irrelevant to Judaism. Abraham is not told to BELIEVE in God, but to walk with God. What is important to Judaism is action, not belief. Doing the right things for the wrong reasons is viewed as sinful (or at best, ambiguous) in Christianity; but in Judaism, doing the right things for the wrong reasons still means you’ve done the right things. Thus, being Jewish is not about believing in God, but about doing the right things. (I decline to get into the discussion of what the “right” things are, since different sects of Judaism have different thoughts on this issue.) "
This is wrong on almost every count.
First of all, the author ought to know that the term “belief” in the sense of affirming that which is empirically unprovable or counter to rational thought, is almost unknown to the biblical mind. If one understands belief as an inner spiritual posture of faith toward God, then “belief” is central to Judaism.
(the Hebrew word “emunah” can be translated as belief, faith, trust, etc…
The origin of “belief” is found in its German root “beliebt” beloved. Abraham did not have to “believe” in God, because he knew God, loved God, trusted God. If was NOT only Abraham’s actions that counted, but his inner state.
Re Abraham: see Gen 15:6, “And Abraham believed in God . . .”
See Exodus, 14:31: “and they believed in God, and Moses his servant”
The commandments to know God, to love God, to observe the Divine way (derech hashem) are all synonymous with the religious notions of belief and faith.
The question of doing the right thing for the wrong reason is best expressed in the dictum, “im lo lishma, ba lishma” if one does not do something for the right reason, by doing it one will come to the right reason. Judaism is not satisfied with doing right only – eventually one ought to come to the right motivation.
See Sa’adia Gaon’s Sefer Emunot veDeot – “The Book of Belief and Opinions” this classic of Jewish theology stresses the importance of right beliefs and opinions.
In fact, every classic of Jewish theology that comes to mind – Guide for the Perplexed, Kuzari, etc. stresses proper belief, as well as every book of Mussar, and certainly in the spiritual tradition.
Relationship with God is at the core of the Jewish tradition: loving God, trusting/believing in God, and performing ritual deeds that help us maintain that love and consciousness, and from that, living a life of righteousness, are core to the Jewish tradition. Both are core; you can’t separate one from the other.