Isaac Asimov (1920 – 1992) was an American Biochemist of Russian origin. Almost throughout out his professional career he was on the faculty of Boston University. However he is best known as one of the most prolific writers of our times. He scribed over five hundred books and published over ninety thousand letters. Most of his writings are science fiction stories and novels and popular science essays.

Asimov was an atheist, a humanist and a rationalist. His views on God, religion and practices were very forthright and down-to-earth. Though he did not oppose religious beliefs in others he was very critical of superstitions and pseudoscientific beliefs which were generally accepted as truth with passage of time. He was one of the founders of the Committee for the Scientific Investigations into Claims of the Paranormal (CSICOP) which is now known as Committee for Skeptical Inquiry (CSI).

Asimov preferred to be labeled as a rationalist rather than an atheist as the latter may imply ignorance. These statements are relevant in this context.

Emotionally I am an atheist. I don't have the evidence to prove that God doesn't exist, but I so strongly suspect he doesn't that I don't want to waste my time.
 
I prefer rationalism to atheism. The question of God and other objects-of-faith are outside reason and play no part in rationalism, thus you don't have to waste your time in either attacking or defending
 
He attacked the shortsightedness of believers and theists who always tended to find fault with science and scientists. According to Asimov science is nothing but systematic accumulation of knowledge and science never did claim to be absolutely true as reflected in these statements.

There are many aspects of the universe that still cannot be explained satisfactorily by science; but ignorance only implies ignorance that may someday be conquered. To surrender to ignorance and call it God has always been premature, and it remains premature today.
 
I believe in evidence. I believe in observation, measurement, and reasoning, confirmed by independent observers. I'll believe anything, no matter how wild and ridiculous, if there is evidence for it. The wilder and more ridiculous something is, however, the firmer and more solid the evidence will have to be.
 
Asimov did extensively study the Bible and wrote a book in two volumes “Asimov’s guide to Bible” covering the Old Testament and The New Testament. His summary view of the Bible is “Properly read, the Bible is the most potent force for atheism ever conceived.”
 
It is an important fact that Isaac Asimov’s parents were highly religious and observed orthodox Jewish traditions. Remarkably, however, they did not force any of their of beliefs on the young Isaac. This facilitated Isaac to think freely and form his own opinions. Perhaps if the parents’ convictions were thrust on him his thoughts would have got diluted. This point is very well made by Astha Prakash in a recently published a well written article in this web site (see the link below)
 
https://www.boloji.com/articles/14016/atheism-the-religion-of-reason