رَبَّنَآ أَفْرِغْ عَلَیْنَا صَبْراً وَثَبِّتْ أَقْدَامَنَا وَانصُرْنَا عَلَى القَوْمِ الكَافِرِینَ
Our Rabb! Fill our hearts with steadfastness, make our steps firm, and help us (give us victory) against the against the people who deny the truth!
In order to achieve steadfastness with our good efforts and endeavours, we need to ask Allah swt for His help and mercy for if He is with us, everything will become easy. This dua is an excellent way to pray for steadfastness and nusrah of Allah swt.
Quran 2:250