Evidence from Qur'an and Sunnah
 

Perfection (Ihsan):

Allah says:

]إِنَّ اللّهَ يَأْمُرُ بِالْعَدْلِ وَالإِحْسَانِ وَإِيتَاء ذِي الْقُرْبَى وَيَنْهَى عَنِ الْفَحْشَاء وَالْمُنكَرِ وَالْبَغْيِ يَعِظُكُمْ لَعَلَّكُمْ تَذَكَّرُون[
(النحل: 90)

This means: “Verily, Allah enjoins Al-Adl (i.e. justice and worshipping none but Allah Alone - Islamic Monotheism) and Al-Ihsan [i.e. to be patient in performing your duties to Allah, totally for Allah's sake and in accordance with the Sunnah (legal ways) of the Prophet SAW in a perfect manner], and giving (help) to kith and kin (i.e. all that Allah has ordered you to give them e.g., wealth, visiting, looking after them, or any other kind of help, etc.): and forbids Al-Fahsha' (i.e. all evil deeds, e.g. illegal sexual acts, disobedience of parents, polytheism, to tell lies, to give false witness, to kill a life without right, etc.), and Al-Munkar (i.e. all that is prohibited by Islamic law: polytheism of every kind, disbelief and every kind of evil deeds, etc.), and Al-Baghy (i.e. all kinds of oppression), He admonishes you, that you may take heed.” (16, An-Nahl: 90)

Allah says:

]وَأَحْسِنُوَاْ إِنَّ اللّهَ يُحِبُّ الْمُحْسِنِين[
(البقرة: 195)

This means: “And do good. Truly, Allah loves Al-Muhsinun (the good-doers).” (2, Al-Baqarah: 195)

The Messenger of Allah (peace be upon him) said:

“Verily Allah has prescribed perfection towards everything. So, if you slaughter, let it be in the best manner. When you sacrifice (an animal), do it in a good way. Let one of you sharpen his knife and comfort his sacrificial animal (reduce its pain).” (Reported by Muslim)

Preference:

Allah says:

]وَيُؤْثِرُونَ عَلَى أَنفُسِهِمْ وَلَوْ كَانَ بِهِمْ خَصَاصَةٌ وَمَن يُوقَ شُحَّ نَفْسِهِ فَأُوْلَئِكَ هُمُ الْمُفْلِحُون[ (الحشر: 9)

This means: “And give them (emigrants) preference over themselves, even though they were in need of that. And whosoever is saved from his own covetousness, such are they who will be the successful.” (59, Al-Hashr: 9)

The Prophet (peace be upon him) said:

“None amongst you is a truthful believer until he likes for his brother which he loves for himself.” (Reported by Al-Bukhari and Muslim)

Sincerity:

Allah says:

]أَلا لِلَّهِ الدِّينُ الْخَالِص[
(الزمر: 3)

This means: “Surely, the religion (i.e. the worship and the obedience) is for Allah only.” (39, Az-Zumar: 3)

Allah says:

]قُلْ إِنِّي أُمِرْتُ أَنْ أَعْبُدَ اللَّهَ مُخْلِصًا لَّهُ الدِّين[
(الزمر: 11)

This means: “Say (O Muhammad SAW): "Verily, I am commanded to worship Allah (Alone) by obeying Him and doing religious deeds sincerely for Allah's sake only and not to show off, and not to set up rivals with Him in worship.''” (39, Az-Zumar: 11)

Allah says:

]قُلِ اللَّهَ أَعْبُدُ مُخْلِصًا لَّهُ دِينِي[
(الزمر: 14)

This means: “Say (O Muhammad SAW) ''Allah Alone I worship by doing religious deeds sincerely for His sake only and not to show-off, and not to set up rivals with Him in worship.''” (39, Az-Zumar: 14)

Allah says:

]وَمَا أُمِرُوا إَِّلا لِيَعْبُدُوا اللَّهَ مُخْلِصِينَ لَهُ الدِّينَ حُنَفَاء وَيُقِيمُوا الصَّلاةَ وَيُؤْتُوا الزَّكَاةَ وَذَلِكَ دِينُ الْقَيِّمَةِ[
(البينة: 5)

This means: “And they were commanded not, but that they should worship Allah, and worship none but Him Alone (abstaining from ascribing partners to Him), and perform As-Salah (Iqamat-as-Salah) and give Zakah: and that is the right religion.” (98, Al-Bayyinah: 5)

Allah says:

]إِنَّمَا نُطْعِمُكُمْ لِوَجْهِ اللَّهِ لا نُرِيدُ مِنكُمْ جَزَاء وَلا شُكُورًا[
(الإنسان: 9)

This means: “We feed you seeking Allah's Countenance only. We wish for no reward, nor thanks from you.” (76, Al-Insan: 9)

The Prophet (peace be upon him) said:

“The luckiest person who will have my intercession on the Day of Resurrection will be the one who said sincerely from the bottom of his heart: None has the right to be worshipped but Allah.”
(Reported by Al-Bukhari)

The Prophet (peace be upon him) said:

“He who is consulted should be trustworthy.”
(Reported by At-Tirmidhi)

Trust:

Allah says:

]اللَّهُ لا إِلَهَ إِلاَ هُوَ وَعَلَى اللَّهِ فَلْيَتَوَكَّلِ الْمُؤْمِنُونَ[
(التغابن: 13)

This means: “Allah! La ilaha illa Huwa (none has the right to be worshipped but He), and in Allah (Alone), therefore, let the believers put their trust.” (64, At-Taghabun: 13)

Allah says:

]ِإِنِ الْحُكْمُ إِلاَّ لِلّهِ عَلَيْهِ تَوَكَّلْتُ وَعَلَيْهِ فَلْيَتَوَكَّلِ الْمُتَوَكِّلُون[
(يوسف: 67)

This means: “Verily! The decision rests only with Allah. In him, I put my trust and let all those that trust, put their trust in Him.” (12, Yusuf: 67)

Allah says:

]فَبِمَا رَحْمَةٍ مِّنَ اللّهِ لِنتَ لَهُمْ وَلَوْ كُنتَ فَظًّا غَلِيظَ الْقَلْبِ لاَنفَضُّواْ مِنْ حَوْلِك فَاعْفُ عَنْهُمْ وَاسْتَغْفِرْ لَهُمْ وَشَاوِرْهُمْ فِي الأَمْرِ فَإِذَا عَزَمْت فَتَوَكَّلْ عَلَى اللّهِ إِنَّ اللّهَ يُحِبُّ الْمُتَوَكِّلِينَ[ 
(آل عمران: 159)

This means: “And by the Mercy of Allah, you dealt with them gently. And had you been severe and harsh­hearted, they would have broken away from about you; so pass over (their faults), and ask (Allah's) Forgiveness for them; and consult them in the affairs. Then when you have taken a decision, put your trust in Allah, certainly, Allah loves those who put their trust (in Him).” (3, Al-`Imran: 159)

Allah says:

]فَإِن تَوَلَّوْاْ فَقُلْ حَسْبِيَ اللّهُ لا إِلَـهَ إِلاَّ هُوَ عَلَيْهِ تَوَكَّلْتُ وَهُوَ رَبُّ الْعَرْشِ الْعَظِيم[ (التوبة: 129)

This means: “But if they turn away, say (O Muhammad SAW): “Allah is sufficient for me. La ilaha illa Huwa (none has the right to be worshipped but He), in Him I put my trust and He is the Lord of the Mighty Throne.”
(9, At-Tawbah: 129)

Allah says:

]وَمَن يَتَوَكَّلْ عَلَى اللَّهِ فَهُوَ حَسْبُهُ[
(الطلاق: 3)

This means: “And whosoever puts his trust in Allah, then He will suffice him.” (65, At-Talaq: 3)

There are other verses that urge Muslims to put their trust in Allah.

The Messenger of Allah (peace be upon him) said:

“If you all pin your trust in Allah with due reliance, He will certainly give you provision as He supplies provisions to birds who get up hungry in the morning and return with full belly at dusk.” (Reported by At-Tirmidhi)

The Prophet Muhammad (peace be upon him) said about the seventy thousands who shall enter Paradise without being taken to account and torment:
“They are those who do not pronounce (non-Islamic) Ruqyah on others, nor seek Ruqyah to be pronounced to them (as a means for protection from evils) nor believe in evil omens, but trust in their Lord.” (Reported by Al-Bukhari and Muslim)

The Messenger of Allah (peace be upon him) said:

“When a man goes out of his house and utters: ‘In the Name of Allah; I trust in Allah; there is no might and no power (to resist evil) but in Allah’, the following (words) will be said to him at that time: ‘You are guided, defended and protected.’ And the devil will go far away from him.” (Reported by Abu Dawud)

Truthfulness:

Allah says:

]يَا أَيُّهَا الَّذِينَ آمَنُواْ اتَّقُواْ اللّهَ وَكُونُواْ مَعَ الصَّادِقِينَ[
(التوبة: 119)

This means: “O you who believe! Be afraid of Allah, and be with those who are true (in words and deeds).” (9, At-Tawbah: 119)

Allah says:

]وَالَّذِي جَاء بِالصِّدْقِ وَصَدَّقَ بِهِ أُوْلَئِكَ هُمُ الْمُتَّقُونَ[
(الزمر: 33)

This means: “And he (Muhammad SAW) who has brought the truth (this Qur'an and Islamic Monotheism) and (those who) believed therein (i.e. the true believers of Islamic Monotheism), those are Al- Muttaqun (the pious and righteous persons).” (39, Az-Zumar: 33)

Allah says:

]ِمِنَ الْمُؤْمِنِينَ رِجَالٌ صَدَقُوا مَا عَاهَدُوا اللَّهَ عَلَيْهِ فَمِنْهُم مَّن قَضَى نَحْبَهُ وَمِنْهُم مَّن يَنتَظِرُ وَمَا بَدَّلُوا تَبْدِيلا[
(الأحزاب: 23)

This means: “Among the believers are men who have been true to their covenant with Allah [i.e. they have gone out for Jihad (holy fighting), and showed not their backs to the disbelievers], of them some have fulfilled their obligations (i.e. have been martyred), and some of them are still waiting, but they have never changed [i.e. they never proved treacherous to their covenant which they concluded with Allah] in the least.” (33, Al-Ahzab: 23)

The Holy Prophet (peace be upon him) said:

“Truth leads to piety, and piety leads to Paradise. A man persists in telling the truth till he is enrolled with Allah as a truthful man. Falsehood leads to vice, and vice leads to the Fire (Hell). A person goes on telling lies till he is recorded to be a liar (in the Sight of) Allah.” (Reported by Muslim)

The Prophet (peace be upon him) said:

“Should not I inform you of the most grievous of the grave sins?” (The Prophet) repeated it three times, and then said: Associating anyone with Allah, and disobedience to parents. The Prophet (peace be upon him) was reclining, then he sat up and said,''And false testimony, or false utterance'', and repeated it so many times that we wished that he should become silent.” (Reported by Al-Bukhari and Muslim)