It has been reported about Hadhrat Uthmaan (Radhiallahu Anhu) that when he would stand over a grave, he would weep so bitterly that his beard would get wet with tears.
Someone asked him, “You do not weep so severely when you remember Jannah and Jahannam as you do when you are reminded about the grave.” He replied, “I have heard Rasulullah (Sallallahu Alaihi Wasallam) saying, "The grave is the initial stage of the Aakhirah; if one escapes punishment in it, all the following stages are much easier, but if one does not escape punishment in the grave, all the next stages are severer than it.’ I also heard him saying, “I have never seen a sight more horrifying than that of the grave.” (Fazaail Sadaqaat pg. 568)