Throughout the history of humanity God has given guidance to peoples through prophets.
The sin of disbelief is when you shut out the possibility that Islam is genuine divine guidance to humanity even when provided with arguments & evidence that would convince any reasonable person. i.e. when your doubts keeping you from accepting Islam become unreasonable; when (as the Arabic word for a disbeliever literally means) you cover up what you know to be the truth.
This web site aims to provide you with such arguments and evidence. It is just a few clicks away...
OK then, convince me - why should I accept Islam?