Belief in God has a personal dimension, but it is not merely subjective in the way taste in food or preference in music is subjective. Islam treats faith as a response of the whole human being - mind, conscience, experience, and revelation - to a reality that is true whether or not a person accepts it.
The strongest form of the concern
The argument is usually put like this: people inherit religion from family and culture; sincere believers in different faiths report deep spiritual experiences; and no one can put God in a laboratory or measure Him as we measure physical objects. So, the critic says, belief in God may be meaningful, comforting, and morally useful, but it remains personal. It tells us about the believer's inner life, not about the world outside the believer.
This is a serious argument. It rightly warns us against confusing emotion with proof, or social habit with truth. A Muslim should accept that some people believe for weak reasons, just as some people disbelieve for weak reasons. The question, though, is not whether belief can be held subjectively. It can. The question is whether belief in God is only subjective. That is a much stronger claim, and it does not follow.
Islam does not base faith on feeling alone
The Quran repeatedly invites people to look, think, compare, and reason. It points to the existence of the universe, its order, the dependence of created things, the moral awareness within the human being, and the inability of idols or imagined powers to create or sustain anything.
Were they created by nothing, or were they themselves the creators? Or did they create the heavens and the earth? Rather, they are not certain.
Quran 52:35-36
Indeed, in the creation of the heavens and the earth, and the alternation of the night and the day... are signs for people who use reason.
Quran 2:164
These are not appeals to private mood. They are public signs. A person may refuse their conclusion, but the reasoning is about shared reality: why anything exists, why the world is intelligible, why minds can know, and why moral obligation feels deeper than social preference.
The personal side is real, but not the whole case
Islam also says that human beings have an innate recognition of God, though it can be covered, confused, or redirected. The Prophet (PBUH) said:
Every child is born upon the fitrah, then his parents make him a Jew or a Christian or a Magian.
Sahih al-Bukhari and Sahih Muslim
This does not mean every person is born with a fully formed theology. It means the human soul is naturally receptive to its Creator. That inner recognition matters, just as conscience matters. But conscience alone can be mistaken or numbed, so Islam joins it to revelation and reflection.
Likewise, personal religious experience can support belief, but it is not the foundation by itself. A believer's peace in prayer is meaningful, yet Islam does not ask the world to accept Islam merely because Muslims feel something. The Quran presents the message of the prophets, the character of the Prophet Muhammad (PBUH), the preservation and power of revelation, and rational signs in creation as converging proofs.
We will show them Our signs in the horizons and within themselves until it becomes clear to them that it is the truth.
Quran 41:53
What the argument proves - and what it does not
The argument proves that belief in God is often personally experienced, culturally influenced, and not reducible to a simple laboratory test. Muslims can accept all of that.
But it does not prove that God is unreal, or that all religious claims are equal, or that reason has nothing to say about the matter. Many real things are not known by laboratory measurement alone: moral truths, other minds, historical events, beauty, and the laws of logic. They are known through appropriate kinds of evidence.
So the fair answer is this: belief in God is personal, but not merely personal; inward, but not irrational; supported by experience, but not dependent on experience alone. Islam calls the human being to believe with humility, thought, and sincerity - not blind inheritance, and not empty sentiment.