(And be not like those who forgot Allah, and He caused them to forget themselves.) meaning, do not forget the remembrance of Allah, the Exalted, otherwise, He will make you forget to perform the good deeds that benefit you in your return, because the recompense is equated with the action. This is why Allah the Exalted said,

﴿أُولَـئِكَ هُمُ الْفَـسِقُونَ﴾

(Those are the rebellious.) referring to those who rebel against obedience to Allah, who will earn destruction on the Day of Resurrection and failure upon their return,

﴿يأَيُّهَا الَّذِينَ ءَامَنُواْ لاَ تُلْهِكُمْ أَمْوَلُكُمْ وَلاَ أَوْلَـدُكُمْ عَن ذِكْرِ اللَّهِ وَمَن يَفْعَلْ ذَلِكَ فَأُوْلَـئِكَ هُمُ الْخَـسِرُونَ ﴾

(O you who believe! Let not your properties or your children divert you from the remembrance of Allah. And whosoever does that, then they are the losers.)(63:9)

source:
Tafseer Ibn Katheer Online
http://abdurrahman.org/qurantafseer/ibnkathir/ibnkathir_web/59.53247.html