The remembrance of Allah (swt) is the cornerstone for the believers, while they should also do the appropriate effort. Hence, they must stand firm, face challenges, and be fully prepared and have complete courage and patience, all while remembering Allah (swt), for He is the Ultimate Supporter.
(لَّعَلَّكُمْ تُفْلِحُونَ) (That you may be successful): Success and triumph will only be for the believers.