In the Name of Allah, the Gracious, the Merciful
Imam al-Nawawi records in his book Meadows of the Righteous:
باب في الاستقامة
Chapter on integrity.
Source: Riyāḍ al-Ṣāliḥīn 1/38
Allah Almighty said:
فَاسْتَقِمْ كَمَا أُمِرْتَ وَمَن تَابَ مَعَكَ وَلَا تَطْغَوْا إِنَّهُ بِمَا تَعْمَلُونَ بَصِيرٌ
So be steadfast as you are commanded, O Prophet, along with those who turn in submission to Allah with you. And do not transgress. Surely He is All-Seeing of what you do.
Surat Hud 11:112
And Allah said:
إِنَّ الَّذِينَ قَالُوا رَبُّنَا اللَّهُ ثُمَّ اسْتَقَامُوا تَتَنَزَّلُ عَلَيْهِمُ الْمَلَائِكَةُ أَلَّا تَخَافُوا وَلَا تَحْزَنُوا وَأَبْشِرُوا بِالْجَنَّةِ الَّتِي كُنتُمْ تُوعَدُونَ نَحْنُ أَوْلِيَاؤُكُمْ فِي الْحَيَاةِ الدُّنْيَا وَفِي الْآخِرَةِ وَلَكُمْ فِيهَا مَا تَشْتَهِي أَنفُسُكُمْ وَلَكُمْ فِيهَا مَا تَدَّعُونَ نُزُلًا مِّنْ غَفُورٍ رَّحِيمٍ
Surely those who say, ‘Our Lord is Allah,’ and then remain steadfast, the angels descend upon them, saying, ‘Do not fear, nor grieve. Rather, rejoice in the good news of Paradise, which you have been promised. We are your supporters in this worldly life and in the Hereafter. There you will have whatever your souls desire, and there you will have whatever you ask for, an accommodation from the All-Forgiving, Most Merciful.’
Surat Fussilat 41:30-32
And Allah said:
إِنَّ الَّذِينَ قَالُوا رَبُّنَا اللَّهُ ثُمَّ اسْتَقَامُوا فَلَا خَوْفٌ عَلَيْهِمْ وَلَا هُمْ يَحْزَنُونَ أُولَٰئِكَ أَصْحَابُ الْجَنَّةِ خَالِدِينَ فِيهَا جَزَاءً بِمَا كَانُوا يَعْمَلُونَ
Surely those who say, ‘Our Lord is Allah,’ and then remain steadfast, there will be no fear for them, nor will they grieve. It is they who will be the residents of Paradise, staying there forever, as a reward for what they used to do.
Surat al-Ahqaf 46:13-14
Sufyan ibn Abdullah reported: I said, “O Messenger of Allah, tell me of a word in Islam I will not need to ask of anyone after you.” The Messenger of Allah, peace and blessings be upon him, said:
قُلْ آمَنْتُ بِاللَّهِ فَاسْتَقِمْ
Say, ‘I have faith in Allah,’ and then remain steadfast.
Source: Ṣaḥīḥ Muslim 38, Grade: Sahih
Aisha reported: The Messenger of Allah, peace and blessings be upon him, said:
سَدِّدُوا وَقَارِبُوا وَأَبْشِرُوا فَإِنَّهُ لَنْ يُدْخِلَ الْجَنَّةَ أَحَدًا عَمَلُهُ
Follow the right course, be devoted, and give glad tidings. Verily, none of you will enter Paradise by his deeds alone.
They said, “Not even you, O Messenger of Allah?” The Prophet said:
وَلَا أَنَا إِلَّا أَنْ يَتَغَمَّدَنِيَ اللَّهُ مِنْهُ بِرَحْمَةٍ وَاعْلَمُوا أَنَّ أَحَبَّ الْعَمَلِ إِلَى اللَّهِ أَدْوَمُهُ وَإِنْ قَلَّ
Not even myself, unless Allah grants me His mercy. Know that the most beloved deed to Allah is done regularly, even if it is small.
Source: Ṣaḥīḥ al-Bukhārī 6464, Grade: Muttafaqun Alayhi
Success comes from Allah, and Allah knows best.