Quoted from the book (An Hour with Ghosts) ByMohammed-Ali Hassan Al-Hilli
If you like to be safe of the torment and to win the Gardens, then you should follow the example of the prophets and saints in monotheism and serving God alone, then you will succeed; but never share or associate any of the prophets or saints together with God in the worship; because you will then lose and your work will be in vain.

God – be glorified – said in the Quran, at the end of soora or chapter 18: 110
فَمَن كَانَ يَرْجُو لِقَاء رَبِّهِ فَلْيَعْمَلْ عَمَلًا صَالِحًا وَلَا يُشْرِكْ بِعِبَادَةِ رَبِّهِ أَحَدًا
The explanation:
(Then let him, who hopes to meet his Lord, work righteous works and associate none in worshipping his Lord.)

The servitude to God is of many kinds; the prayer and fasting are some kinds of servitude or worship; the vowing to God is a kind of servitude; to mention God with celebration and glorifying is a kind of servitude; sanctifying and glorifying God is a another kind of servitude or worship, and seeking His help is another form of worship.

Therefore, if you mention a prophet or a saint, seeking his help when you stand up and sit down, then you will share [him with God.] It is not allowed to seek their help, even if you say: "O Mohammed [help me!]" So in spite of that you everyday recite His saying – be exalted – in the Quran 1: 5
إِيَّاكَ نَعْبُدُ وإِيَّاكَ نَسْتَعِينُ
The explanation:
(You [alone] we worship; and You [alone] we ask for help.)
The meaning is: We serve and worship none save Him; and we seek His help [and depend on Him] only, and we seek the help of none save Him.

In this respect, one of the Arab poets said:
"You always utter: " You [alone] we ask for help",
But actually you seek help of those other than God!"

Righteous saints asked the help of God when they stood up and sat down, and they did never ask the help of prophets; similarly the imams and the companions of Prophet Mohammed – salam be to him – did in like manner; so God – be glorified – revealed this Quranic revelation 3: 191:
الَّذِينَ يَذْكُرُونَ اللّهَ قِيَامًا وَقُعُودًا وَعَلَىَ جُنُوبِهِمْ
The explanation:
([Those] who remember God when they stand up, sit down and recline [on their sides] )

It means: They mention God when they stand up, sit down and lie on their sides.

God - be exalted - said in the Quran 33: 41-42
يَا أَيُّهَا الَّذِينَ آمَنُوا اذْكُرُوا اللَّهَ ذِكْرًا كَثِيرًا . وَسَبِّحُوهُ بُكْرَةً وَأَصِيلًا
The explanation:
(O believers, mention God [in celebration] with much mentioning.
And celebrate His praises, morning and evening.)

It means: Mention and remember Him day and night; i.e. Mention and remember Him always.

Therefore, God –be glorified – said
اذْكُرُوا اللَّهَ ذِكْرًا كَثِيرًا
i.e. (Mention God [in celebration] with much mentioning); but He
did not say: Mention anyone of the saints or anyone of the apostles and the prophets with much mentioning and remembrance.

Moreover, God - be exalted - said in the Quran 7: 205
وَاذْكُر رَّبَّكَ فِي نَفْسِكَ تَضَرُّعاً وَخِيفَةً وَدُونَ الْجَهْرِ مِنَ الْقَوْلِ بِالْغُدُوِّ وَالآصَالِ
The explanation:
(Remember your Lord [with glorification] within your soul, supplicating and fearing [Him], not loud of voice, by day and night, and don't be one of the heedless [of His remembrance.] )

It means: Remember and mention Him always.

God – be glorified – said also in the Quran 2: 200
فَإِذَا قَضَيْتُم مَّنَاسِكَكُمْ فَاذْكُرُواْ اللّهَ كَذِكْرِكُمْ آبَاءكُمْ أَوْ أَشَدَّ ذِكْرًا
The explanation:
(And when you have completed your devotions [of the pilgrimage], then mention God [in celebration] as you mention your fathers* or with a more lively mentioning.)
-----------------------------------------------------
[*It was the custom of the pagan Arab to praise their forefathers at the conclusion of the pilgrimage to Mecca.]

In addition, God – be exalted – said in the Quran 18: 24
وَاذْكُر رَّبَّكَ إِذَا نَسِيتَ وَقُلْ عَسَى أَن يَهْدِيَنِ رَبِّي لِأَقْرَبَ مِنْ هَذَا رَشَدًا
The explanation:
(And mention your Lord [asking His forgiveness] when you forget [some duties, and with repentance when you make mistake],

and say: "I hope that my Lord will guide me within a shorter time than this to the right guidance [to answer their question].")

[It means: And say: My Lord, remind me about what I have forgotten. So He will remind you.]

Therefore, to seek the help of prophets and saints is not allowed, and actually it is a sort of associating and sharing [them with God in worship]; while God – be glorified – considers the sharing or associating with God or the polytheism as the greatest sin.

Read more
http://quran-ayat.com/hour/an_hour_w...ouls_of_Saints