يَا أَيُّهَا الَّذِينَ آمَنُوا إِن تَنصُرُوا اللَّهَ يَنصُرْكُمْ وَيُثَبِّتْ أَقْدَامَكُمْ

This verse establishes a reciprocal relationship between believers and Allah. "Supporting Allah" means supporting His religion, His cause, His messengers, and His commandments - essentially living and working for the establishment of divine guidance. In return, Allah promises two things: His support (nasr) and firm footing (tathbit al-aqdam). Divine support includes help in all aspects of life, while "firm footing" means steadfastness in faith, stability in difficult times, and success in endeavors. This teaches that Allah's help is conditional upon our support of His cause, that working for Allah's religion brings divine assistance in return, that Allah strengthens those who strive for His sake, and that supporting Allah's cause provides both worldly success and spiritual stability. The verse encourages believers to actively work for Islam and divine values, with confidence that Allah will support and strengthen them in return.