Increase of faith

وَلَمَّا رَءَا ٱلْمُؤْمِنُونَ ٱلْأَحْزَابَ قَالُوا۟ هَـٰذَا مَا وَعَدَنَا ٱللَّهُ وَرَسُولُهُۥ وَصَدَقَ ٱللَّهُ وَرَسُولُهُۥ ۚ وَمَا زَادَهُمْ إِلَّآ إِيمَـٰنًا وَتَسْلِيمًا

And when the believers saw the companies, they said, "This is what Allāh and His Messenger had promised us, and Allāh and His Messenger spoke the truth." And it increased them only in faith and acceptance.

هُوَ ٱلَّذِىٓ أَنزَلَ ٱلسَّكِينَةَ فِى قُلُوبِ ٱلْمُؤْمِنِينَ لِيَزْدَادُوٓا۟ إِيمَـٰنًا مَّعَ إِيمَـٰنِهِمْ ۗ وَلِلَّهِ جُنُودُ ٱلسَّمَـٰوَٰتِ وَٱلْأَرْضِ ۚ وَكَانَ ٱللَّهُ عَلِيمًا حَكِيمًا

It is He who sent down tranquility into the hearts of the believers that they would increase in faith along with their [present] faith. And to Allāh belong the soldiers of the heavens and the earth, and ever is Allāh Knowing and Wise.