The idea of blind faith is in part to reinforce the idea of faith.
People say they have faith in the justice system or employees etc. But if they lose a case or get fired, they curse the system.
Such faith which is here today and gone tomorrow is not faith, but temporary hope that things will turn out well.
Faith in Guru should be the way roots clinch to mud, even if you uproot the plant from soil, the roots don't let go.
Here are Shabads regarding that:
ਰੂਪੁ ਸਤਿ ਜਾ ਕਾ ਸਤਿ ਅਸਥਾਨੁ ॥
His form is true, and true is His place.
ਪੁਰਖੁ ਸਤਿ ਕੇਵਲ ਪਰਧਾਨੁ ॥
Reference:: Sikh Philosophy Network http://www.sikhphilosophy.net/showthread.php?t=36969
His personality is true - He alone is supreme.
ਕਰਤੂਤਿ ਸਤਿ ਸਤਿ ਜਾ ਕੀ ਬਾਣੀ ॥
His acts are true, and true is His Word.
ਸਤਿ ਪੁਰਖ ਸਭ ਮਾਹਿ ਸਮਾਣੀ ॥
The True Lord is permeating all.
ਸਤਿ ਕਰਮੁ ਜਾ ਕੀ ਰਚਨਾ ਸਤਿ ॥
True are His actions; His creation is true.
ਮੂਲੁ ਸਤਿ ਸਤਿ ਉਤਪਤਿ ॥
His root is true, and true is what originates from it.
ਸਤਿ ਕਰਣੀ ਨਿਰਮਲ ਨਿਰਮਲੀ ॥
True is His lifestyle, the purest of the pure.
ਜਿਸਹਿ ਬੁਝਾਏ ਤਿਸਹਿ ਸਭ ਭਲੀ ॥
All goes well for those who know Him.
ਸਤਿ ਨਾਮੁ ਪ੍ਰਭ ਕਾ ਸੁਖਦਾਈ ॥
The True Name of God is the Giver of peace.
ਬਿਸ੍ਵਾਸੁ ਸਤਿ ਨਾਨਕ ਗੁਰ ਤੇ ਪਾਈ ॥੬॥
Nanak has obtained true faith from the Guru. ||6||
(Sukhmani Sahib - Ang 284)
And:
ਦੂਜੈ ਭਾਇ ਲਗੇ ਦੁਖੁ ਪਾਇਆ ॥
Attached to the love of duality, one only incurs pain.
ਬਿਨੁ ਸਬਦੈ ਬਿਰਥਾ ਜਨਮੁ ਗਵਾਇਆ ॥
Without the Word of the Shabad, one's life is wasted away in vain.
ਸਤਿਗੁਰੁ ਸੇਵੈ ਸੋਝੀ ਹੋਇ ॥
Serving the True Guru, understanding is obtained,
ਦੂਜੈ ਭਾਇ ਨ ਲਾਗੈ ਕੋਇ ॥੧॥
And then, one is not attached to the love of duality. ||1||
ਮੂਲਿ ਲਾਗੇ ਸੇ ਜਨ ਪਰਵਾਣੁ ॥
Those who hold fast to their roots, become acceptable.
ਅਨਦਿਨੁ ਰਾਮ ਨਾਮੁ ਜਪਿ ਹਿਰਦੈ ਗੁਰ ਸਬਦੀ ਹਰਿ ਏਕੋ ਜਾਣੁ ॥੧॥ ਰਹਾਉ ॥
Night and day, they meditate within their hearts on the Lord's Name; through the Word of the Guru's Shabad, they know the One Lord. ||1||Pause||
ਡਾਲੀ ਲਾਗੈ ਨਿਹਫਲੁ ਜਾਇ ॥
One who is attached to the branch, does not receive the fruits.
ਅੰਧੀ ਕੰਮੀ ਅੰਧ ਸਜਾਇ ॥
For blind actions, blind punishment is received.
ਮਨਮੁਖੁ ਅੰਧਾ ਠਉਰ ਨ ਪਾਇ ॥
The blind, self-willed manmukh finds no place of rest.
ਬਿਸਟਾ ਕਾ ਕੀੜਾ ਬਿਸਟਾ ਮਾਹਿ ਪਚਾਇ ॥੨॥
He is a maggot in manure, and in manure he shall rot away. ||2||
ਗੁਰ ਕੀ ਸੇਵਾ ਸਦਾ ਸੁਖੁ ਪਾਏ ॥
Reference:: Sikh Philosophy Network http://www.sikhphilosophy.net/showthread.php?t=36969
Serving the Guru, everlasting peace is obtained.
ਸੰਤਸੰਗਤਿ ਮਿਲਿ ਹਰਿ ਗੁਣ ਗਾਏ ॥
Joining the True Congregation, the Sat Sangat, the Glorious Praises of the Lord are sung.
ਨਾਮੇ ਨਾਮਿ ਕਰੇ ਵੀਚਾਰੁ ॥
One who contemplates the Naam, the Name of the Lord,
ਆਪਿ ਤਰੈ ਕੁਲ ਉਧਰਣਹਾਰੁ ॥੩॥
Saves himself, and his family as well. ||3||
ਗੁਰ ਕੀ ਬਾਣੀ ਨਾਮਿ ਵਜਾਏ ॥
Through the Word of the Guru's Bani, the Naam resounds;
ਨਾਨਕ ਮਹਲੁ ਸਬਦਿ ਘਰੁ ਪਾਏ ॥
O Nanak, through the Word of the Shabad, one finds the Mansion of the Lord's Presence
ਗੁਰਮਤਿ ਸਤ ਸਰਿ ਹਰਿ ਜਲਿ ਨਾਇਆ ॥
Under Guru's Instruction, bathe in the Pool of Truth, in the Water of the Lord;
ਦੁਰਮਤਿ ਮੈਲੁ ਸਭੁ ਦੁਰਤੁ ਗਵਾਇਆ ॥੪॥੫॥੪੪॥
Thus the filth of evil-mindedness and sin shall all be washed away. ||4||5||44||
(Sri Guru Granth Sahib, Ang 362)