Only God knows what they have seen
The master of the martyrs, Imam Husain (a), chose to bear all the suffering that he did in the event of Karbala with his own free will. Why do you think he chose to bear it, when on several occasions the option of defeating his enemy through divine help was presented to him?
Imam Husain (a) had two options: he could either attain a physical victory against the enemies of Allah (swt) or he could attain the level of liqaAllah (the special meeting with Allah) by fulfilling the promise which he made with the Almighty. The Imam (a), with his own free will, selected the option which carried greater value in the eyes of Allah (swt). He knew that his martyrdom, despite looking like a defeat, was in reality a hidden victory with a more lasting impact and benefit for Islam and the society.
What is so great in liqaAllah, that we see even the child of Imam Hasan (a), Hazrat Qasim, considering death in this path to be sweeter than honey? That is no small statement!
Another example of someone aspiring towards liqaAllah on the day of Ashura was al-Abbas (a). He showed the enemy that he has selected the path of martyrdom due to his belief and his own free will, not because of compulsion or threat. He showed that has chosen the path of bravery, love and martyrdom, in contrast to the likes of Umar ibn Sa’ad who chose the path of greediness and the kingdom of Rey that was promised to him. By sacrificing himself, al- Abbas (a) wanted to show the people the superiority of the love of Allah (swt) and His Awliya (a) over the fleeting pleasures of this world. His sacrifice demonstrated that love for Allah makes the difficulties of the path of righteousness easier for a person to bear.
The main purpose of the martyrs of Karbala was to attain liqaAllah, for which they strove, even if it meant giving their blood. However, we cannot fathom their status near Allah (swt) nor comprehend what their thought and vision was. As it is narrated, Imam Husain (a) showed them their positions in the eternal life before they were martyred. Only Allah (swt) knows what they saw!
It is for us to ponder upon then… while we wish we were also there with them to reach those high levels, how much have we really sacrificed and are we ready to sacrifice so that we can also attain those ranks?