Two brothers speak about how you are always living in fear of not being good enough for heaven as everything you do are being put on a scale of good and bad deeds. No one has assurance of salvation, not even Muhammad. How different it is with the biblical promise that you can have assurance of salvation.
1 John 5:13 I write these things to you who believe in the name of the Son of God so that you may know that you have eternal life.