Is paradise guaranteed if a great spiritual leader leads one’s funeral prayer, or if one dies during the pilgrimage?
No. On this earth no one has a guarantee of paradise. What decides is God’s mercy alone, not who leads the prayer or where one dies.
It is understandable that people look for certainty. When a very devout person leads the funeral prayer for someone, or when someone dies during the pilgrimage, it is tempting to think that paradise is certain for them. Islam teaches, however, that no one on this earth has such a guarantee.
The example of the Holy Prophet Muhammad (saw) makes this clear. God told him about certain bitter enemies that they would not be forgiven, even if he asked forgiveness for them seventy times. That is the verse above. If not even the prayer of the greatest prophet is a guarantee, then the prayer of no other person can be one, however devout they may be.
The same is true of the pilgrimage. Whether someone dies on the way to Mecca, during the rites or afterwards, only God knows what becomes of them. Not every pilgrimage is accepted by God. The outward act alone is not a sure means of salvation.
This is not meant to take away anyone’s hope. A funeral prayer offered by sincere people, and a pilgrimage undertaken with a pure heart, are great blessings. They simply do not replace what truly matters.
In the end it is God’s mercy alone that saves a person. That mercy is vast, but it does not follow places, titles or our own wishes. So one should not rely on outward signs, but live honestly and hope for God’s grace.