If he follows a scholar who is known for being knowledgeable and honest, he is not sinning

Praise
be to Allah

Firstly: 

There is no sin on anyone who follows one of the scholars who
are known for their knowledge and honesty, because he is complying with the
verse in which Allah, may He be glorified and exalted, says (interpretation
of the meaning): “So
ask of those who know the Scripture, if you know not” 
[an-Nahl 16:43]. For the
ordinary Muslim, the verdict of a scholar is like proof, and he must look
for one who has knowledge and follow his fatwa. 

Ash-Shaatibi (may Allah have mercy on him) said in al-Muwaafaqaat
(4/292): 

The fatwas of the mujtahid scholars, for the ordinary
Muslims, are like shar‘i evidence for the mujtahid scholars, the reason
being that for ordinary people, the presence or absence of evidence is all
the same, because they cannot benefit from it at all. Looking at textual
evidence and trying to derive rulings based on it is not something that they
can do, and it is not permissible for them to do that at all. Allah, may He
be exalted, says (interpretation of the meaning): “So
ask of those who know the Scripture, if you know not”
[an-Nahl 16:43]. The
ordinary Muslim is not a scholar, so it is not appropriate for him to do
anything but ask those who have knowledge and refer to them with regard to
the rulings of Islam in general. For him, they are the ones who represent
the Lawgiver, and for him, their rulings are like those of the Lawgiver. End
quote. 

In al-Mawsoo‘ah al-Fiqhiyyah (32/47-49) it says: 

The one who seeks a verdict (fatwa), if he is faced with an
issue, has to ask one who has knowledge and is of good character. 

Ibn ‘Aabideen said, narrating from al-Kamaal ibn al-Humaam:
There is consensus that it is permissible to seek a verdict from scholars
who are known to be qualified to engage in ijtihaad (and derive rulings) and
to be of good character, or who have already been appointed to that position
and people seek their fatwas on various issues and show respect to them. One
should not ask anyone for a fatwa if he thinks that one of these two
attributes are not present in his case – i.e., if he is not qualified to
engage in ijtihaad (and derive rulings) or is not of good character. 

If the one who is seeking a verdict finds more than one
scholar to ask, and all of them are of good character and qualified to issue
fatwas, 

then the majority of fuqaha’ are  of the view that the one
who is seeking a fatwa may choose between them; he may ask whichever of them
he likes and follow his view, and he does not have to examine each one in
order to determine which of them has the greatest knowledge and then ask
him. Rather he may ask the one who has the greatest knowledge, if he wishes,
or if he wishes he may ask one who has less knowledge, even though one who
has greater knowledge is available. The evidence for that is the general
meaning of the verse in which Allah, may He be exalted, says (interpretation
of the meaning): “So
ask of those who know the Scripture, if you know not”
[an-Nahl 16:43].
Moreover, the earlier generations used to ask the Sahaabah even though there
were senior Sahaabah, who were of greater virtue, who they could have gone
and asked. 

If he asks more than one mufti and they all give the same
answer, then he is obliged to follow that if he is comfortable with their
fatwa. If they differ, then there are two views among the fuqaha’ as to how
he should approach the situation: 

the majority of fuqaha’ – the Hanafis, Maalikis, some of the
Hanbalis, Ibn Surayj, as-Sam‘aani and al-Ghazaali among the Shaafa‘is – are
of the view that the ordinary Muslim should not choose, in the sense of
following what he wants and rejecting what he wants; rather he has to
examine their views and see which is more likely to be sound. 

However the more correct view, according to the Shaafa‘is and
some of the Hanbalis, is that it is permissible for the ordinary Muslim to
choose between differing views of muftis, because the duty of the ordinary
Muslim is to follow a scholar, and he is doing that by following the view of
whichever of the muftis he wants. End quote. 

Secondly: 

What you must do is put your question to a scholar who is
well known for his knowledge and honesty, and for being a man of dignity,
then accept his fatwa and adhere to it. It is not permissible to seek out
concessions and the easiest fatwas, except in one case, which is when the
difference between muftis has to do with a minor issue that is subject to
ijtihaad, concerning which there is no text of the Qur’an or Sunnah to
indicate that one view is more likely to be correct than others, and the
only way to find out which view is correct is personal views and pure
ijtihad and examination. In that case there is nothing wrong with finding
out which view offers a concession and following it, if the Muslim needs
that. The Islamic principle states: hardship in complying with a ruling
leads to a fatwa that grants a concession and make things easier. 

It says in Liqaa’aat al-Baab al-Maftooh, by Shaykh Ibn
‘Uthaymeen (meeting no. 46; question no. 2): 

Question: is it permissible to seek fatwas from more than one
scholar? If the fatwas differ, should the one who is seeking a fatwa choose
the easiest or the most prudent? May Allah reward you with good. 

Answer:

it is not permissible for a person, if he has asked a scholar
whose view he trusts for a fatwa, to ask someone else, because this leads to
toying with the religion of Allah and seeking out concessions, as the person
may ask one scholar, then if the answer does not suit him, he asks another
one, and if his answer does not suit him, he asks a third scholar, and so
on. The scholars stated that seeking out concessions is evil. 

But sometimes a person may have access to only one scholar,
so he asks him out of necessity, but his intention is that, if he meets a
scholar who is more trustworthy in terms of his knowledge and religious
commitment than the first one, he will ask him. In this case there is
nothing wrong with him asking the first one out of necessity, then if he
finds one who has more knowledge than him, he may ask him. 

If the scholars give him different fatwas, or if there is a
difference in what he hears of their exhortations and advice – for example –
then he may look for someone who he thinks is closer to the truth in terms
of his knowledge and religious commitment. 

If the two men are equal in terms of knowledge and religious
commitment, in his view, then in this case some of the scholars said that he
should follow that which is more prudent, which is that which is more
strict. 

However it was also suggested that he should follow that
which is easier, and this is the correct view, because if the fatwas are
equal in terms of evidence, then you should follow that which is easier,
because the religion of Allah, may He be glorified and exalted, is based on
ease and simplicity, not on hardship. ‘Aa’ishah (may Allah be pleased with
her) said, describing the Prophet (blessings and peace of Allah be upon
him): he was never given the choice between two things but he chose the
easier of the two, so long as it was not a sin. End quote. 

Based on that, it is not permissible for you to follow the
view of one who gives a concession, unless the following two conditions are
met: 

1.    

that he has not gone against the majority of scholars of
the earlier and later generations, for they are undoubtedly more
knowledgeable and more pious, and it is their views that people should
follow;

2.    

that the evidence of both views should be of equal
strength. In that case you may follow the easier of the two views.

And Allah knows best.

You can also refer to previous answers on this topic on our
website, under the following numbers: 9516,
22652 and 30842.

And Allah knows best.