Whoever Sets a Bad Precedent Will Bear the Burden of Sin of Those Who Do it Until the Day of Resurrection

If a person dies having done actions that were contrary to
Islam, and others such as children, friends, neighbours and so on followed his example, then he bears the burden (of sin) of what he did and
the burden of those who did the same, following his example, without that
detracting from their burden of sin in the slightest. Muslim (1017)
narrated that Jareer ibn ‘Abd-Allah (may Allah be pleased with him) said:
The Messenger of Allah (may the peace and blessings of Allah be upon him) said: “Whoever sets a good precedent in Islam
will have the reward for that and the reward of those who do it after him,
without that detracting from their reward in the slightest. And whoever
sets a bad precedent in Islam will bear the burden of sin for that, and
the burden of those who do it after him, without that detracting from
their burden in the slightest.” 

Ibn ‘Allaan said: 

“Whoever sets a bad precedent in Islam” means sin, even if it
is small, if he does it and his example is followed, or if he promotes it or
helps others to commit it. “Will bear the burden of sin for that”, means,
for having done it. “And the burden of those who do it after him, without
that detracting from their burden in the slightest.” End quote. 

Daleel al-Faaliheen, 2/136 

Shaykh Ibn ‘Uthaymeen said: 

This is a warning against setting a bad precedent, and shows
us that whoever sets a bad precedent will bear the burden of sin for that
and the burden of those who do it, until the Day of Resurrection, even if it
was on a small scale at first, then it became more widespread; he will bear
the burden of its spreading. For example, if one person granted a concession
to one other person with regard to something permissible that became a clear means leading to something impermissible or close to it, if that became
widespread because of the fatwa given to people, then the burden will be
upon him as will the burden of those who did it until the Day of
Resurrection. End quote.

Sharh Riyaadh al-Saaliheen, p.
199  

It was narrated that Ibn Mas‘ood (may Allah be pleased with
him) said: The Messenger of Allah (blessings and peace of Allah be upon him)
said: “No soul is killed unlawfully, but there is a share of the sin on the
first son of Adam, because he was the first one to set the precedent of
killing.”

Narrated by al-Bukhaari (3336) and Muslim (1677). 

Al-Nawawi said: 

This hadeeth represents one of the basic principles of Islam,
which is that anyone who introduces any kind of evil will bear the burden of
sin of everyone who follows his example in doing that until the Day of
Resurrection. End quote. 

So the father who gives his children a bad upbringing and is
a bad example for them, and they follow him in his deviant conduct, will
bear the burden of his children’s sin, because he was the cause of their
deviating; the children will also bear the burden of their own actions in
full and nothing will be detracted from it. 

What this father should have done was to give his children a
good upbringing and fulfil the responsibility that Allah placed upon his
shoulders in the best manner. 

The Messenger of Allah (blessings and peace of Allah be upon
him) said: “Each of you is a shepherd and each of you is responsible for his
flock. … A man is the shepherd of his household and is responsible for his
flock.”

Narrated by al-Bukhaari (7138) and Muslim (1829) 

Shaykh Ibn ‘Uthaymeen said: 

The man is the shepherd of the members of his household, his
wife, his son, his daughter, his sister, his paternal aunt and his maternal
aunt. He is the shepherd of members of his household and he is responsible
for his flock; he must take the best possible care of them because he is
responsible for them. End quote. 

Sharh Riyadh al-Saaliheen, p.
337 

And Allah knows best.