But why do you feel belief equates or begets bias? The definitions of belief and bias, are not similar in remotely such a way as I'm understanding from your comment.

For one "beliefs" are primarily defined in the dictionary as:

• acceptance that a statement is true or that something exists
• something one accepts as true or real; a firmly held opinion or conviction

and secondary as "belief in" as:

• trust, faith, or confidence in someone or something (usually but not strictly referring to religious beliefs)

In these regards, I would think your aim as stated could never succeed, as it is impossible for one to have the opinion that - not any statement is true or that not anything exists, related or otherwise. Simply holding yourself to be a person, and having your own set of goals or standards, (aside from that in itself being a belief structure of its own) believing in yourself or your goals, is in fact acceptance that you are real, and exist, and believe and have conviction in your opinions and goals. So to exist aside from beliefs, of many or any kinds or kind, would make existence as such, impossible.

However if I assume you mean beliefs as they are defined in the secondary definition, more so "belief in" or a "set of beliefs" with a religious connotation.
Still the definition of "bias" doesn't really help your seeming comparative implication.

"Bias" in the noun tense is found as:

• "prejudice in favor of or against one thing, person, or group compared with another, usually in a way considered to be unfair"
• in reference to a bias put on a ball in the sports environment, an irregular shape given to a ball, such as when a Baseball Pitcher throws a curve ball and the rotation and centrifugal forces cause the ball to physically warp to a small degree, or in Tennis to a large degree given the elasticity differences. Resulting in a bias in one direction over another throughout its trajectory. Or in electrical biases via voltage, magnetic field or other factors causing a device to operate over a predetermined range.

And the verb tense to "be biased":

• to feel or show inclination or prejudice for or against someone or something.

So if bias is in favor of or against one thing, person, or group compared with another in an unfair manner, religious bias doesn't fall under this definition as being in favor one against another is not explicit, and the unfair manner is not uniform as per the content of the religions of the world, regardless of the many unfavorable aspects of many religions, favorable aspects as well exist, but not uniformly in any regards. It would almost appear as though your viewpoint would be one of "bias" itself in promoting it as a standard in the way in which you do.
Also, "bias" comes in many forms, some of which aren't of a poor connotation, so certainly holding it as a form of equation to or with "beliefs" both general and specific, is not only ill conceived, but judgemental in form and function thereby far from unhindered or unreasonable in attachment to either.
Besides, who maintained that attachment, both reasonable and unreasonable, was a less than ideal quality in any light. Because love itself can at times seem reasonable and unreasonable, and due to differing perspectives of all individuals, both belief or bias can be seen in both conditions, without or even with regard to the right or wrong of it.