and in the next he will most surely be among the righteous." (Quran 16:120-121).
One of Abraham's main trials was to face the command of Allah to kill his only son.
Upon hearing this command, he prepared to submit to Allah's will. When he was all prepared to do it, Allah revealed to him that his "sacrifice" had already been fulfilled. He had shown that his love for his God superceded all others that he would lay down his own life or the lives of those dear to him in order to submit to God.