There are some Islamic scholars who are hell bent on trying to prove that insurance is not anti-Shariah by nature. In their bid to do so they have claimed that there is no speculation factor as far as the insurance companies are concerned because they rely on the law of large numbers. The scholars compare the insurance contract to al-dhamaan or al-kifaalah (contract of surety or guarantee).
The Islamic scholars who disapprove of insurance have found out that there is no point of comparison between insurance and a contract of guarantee. Al-Dhamaan or the contract of surety or guarantee has to be a philanthropic kind of contract. Otherwise one would be simply paying money for money which is akin to Riba.
In the insurance contract one pays for guarantee regarding something that may either occur or not. This involves gharar and jahaalah which is not permissible in Islam.
Keep Me In Your Prayers.