We are only required to pray the five prayers and fast one month of the year; anything more is optional. Prayer, fasting and pilgrimage are not goals in themselves, but necessary vehicles to higher goals.
On the contrary we are asked to sit and reflect for a long time: “Those who remember Allah while standing or sitting or lying on their sides and give thought to the creation of the heavens and the earth, saying, ‘Our Lord, You did not create this aimlessly; exalted are You!’”
God does not compel a soul beyond what it is able to do. We will not be judged for what we do not know; God will judge us by our level, not someone else’s. Perhaps the key to more certainty is to spend more time reflecting and pondering on the beauty of creation: to go for walks in the hills, through dense woodland or by beautiful winding rivers.
Some of what is stated as Islam is clear cut and factual. For example, there are five things that make up belief: from the Quran it is clear that the universe has a creator called Allah; that there are unseen creatures called angels; that there were Prophets and Messengers; that Books were revealed to those Messengers; and that there will be a Day of Judgement.
Other certainties are that the core mission of all Prophets was for people to uphold justice, not to convert everyone; that prayers, fasting and pilgrimage are not goals in themselves but are necessary vehicles to higher goals; that individual responsibility rests within their ability.
Some of what is stated as Islam is probable. For example, from the Quran it is not clear if there are other creatures on other planets, though when reading you get the feeling that this is the case. Similarly, it is probable that before Adam there were no other human-like creatures.
However some of what is stated as Islam is not true or is at least disputed. Examples are that a woman can be pregnant for more than a year, that the Prophet — peace be upon him — waged war against people who did not wage war against him or that everyone in Arabia became Muslim in his time.
When we separate out what is clear cut and factual from what is not true or disputed, many of the contentious obstacles to belief disappear. The biggest obstacle people face when it comes to belief is not the Quran, but other sources which have been allowed to contradict and undermine it. Saying that something is true because it is found in our books or is old is a problematic approach. It could be true, but it might not be: we have to evaluate things and challenge suspect ideas.
The idea that a person who has tried hard to believe is punished is not from the Quran. Rather the Quran talks about being held accountable according to your level or ability, although of course that doesn’t mean it is easy, for the Quran asks, “Do the people think that they will be left to say, ‘We believe’ and they will not be tested?”
We have to take one thing at a time. Nobody can be certain about absolutely everything. We have to experience things for what they are. When we see things with our heart, we will become certain; if we only see with ours eye, we will never have certainty.