Which takes priority: calling non-Muslims to Islam or calling non-committed Muslims to become religiously committed?

Question

Praise be to Allah.

What appears to be the case based on the general meaning of
the shar‘i evidence concerning that is that calling people to Allah, may He
be exalted, is a communal obligation (fard kifaayah) upon the ummah and it
is an individual obligation (fard ‘ayn) upon every Muslim, according to his
level of ability and knowledge. The Prophet (blessings and peace of Allah be
upon him) said: “Convey from me, even if it is only one verse.”

Narrated by al-Bukhaari, 3461

Ibn Katheer (may Allah have mercy on him) said, in his
commentary on the first in which Allah, may He be exalted, says
(interpretation of the meaning): “Let there arise out of you a group of
people inviting to all that is good (Islam), enjoining Al-Ma‘roof (i.e.
Islamic Monotheism and all that Islam orders one to do) and forbidding
Al-Munkar (polytheism and disbelief and all that Islam has forbidden). And
it is they who are the successful” [Aal ‘Imraan 3:104]:

What is meant by this verse is that there should be a group
of this ummah who carry out this mission; however, that is also obligatory
upon every individual of the ummah according to his means, as it is proven
in Saheeh Muslim that Abu Hurayrah said: The Messenger of
Allah (blessings and peace of Allah be upon him) said: “Whoever
among you sees an evil action, then let him change it with his hand [by
taking action]; if he cannot, then with his tongue [by
speaking out]; and if he cannot, then with his heart – and that is the
weakest of faith.” According to another version: “Beyond that there
is not even a mustard seed’s worth of faith.”

End quote from Tafseer Ibn Katheer, 2/78

Shaykh ‘Abd al-‘Azeez ibn Baaz (may Allah have mercy on him)
said:

The evidence from the Qur’an and Sunnah indicates that it is
obligatory to call people to Allah, may He be glorified and exalted, and
that this is one of the obligatory duties. The evidence for that is
abundant, such as the verses in which Allah, may He be glorified, says
(interpretation of the meaning):

“Let there arise out of you a group of people inviting to
all that is good (Islam), enjoining Al-Ma‘roof (i.e. Islamic Monotheism and
all that Islam orders one to do) and forbidding Al-Munkar (polytheism and
disbelief and all that Islam has forbidden). And it is they who are the
successful”

[Aal ‘Imraan 3:104]

“Invite (mankind, O Muhammad SAW) to the Way of your Lord
(i.e. Islam) with wisdom (i.e. with the Divine Inspiration and the Quran)
and fair preaching, and argue with them in a way that is better”

[an-Nahl 16:125]

“and invite (men) to (believe in) your Lord, and be not of
Al-Mushrikoon (those who associate partners with Allah”

[al-Qasas 28:87]

“Say (O Muhammad SAW): “This is my way; I invite unto
Allah (i.e. to the Oneness of Allah – Islamic Monotheism) with sure
knowledge, I and whosoever follows me (also must invite others to Allah
i.e., to the Oneness of Allah – Islamic Monotheism) with sure knowledge”

[Yoosuf 12:108].

So Allah, may He be glorified, has explained that the
followers of the Messenger (blessings and peace of Allah be upon him) are
those who call people to Allah; they are the people of insight. What is
required, as is well known, is to follow him and adhere to his way, as
Allah, may He be exalted, says (interpretation of the meaning):

“Indeed in the Messenger of Allah (Muhammad SAW) you have
a good example to follow for him who hopes in (the Meeting with) Allah and
the Last Day and remembers Allah much”

[al-Ahzaab 33:21].

The scholars have clearly stated that calling people to
Allah, may He be exalted, is a communal obligation (fard kifaayah) with
regard to the regions in which the callers live, for every region and area
needs the da‘wah (call) and needs people who are active in this field. So it
is a communal obligation; if sufficient numbers of people undertake it, the
duty is waived from the others and for the others da‘wah becomes a confirmed
Sunnah (Sunnah mu’akkadah) and a great righteous deed.

But if the people of a specific area or region do not
undertake da‘wah, the burden of sin is incurred by all of them, and it
becomes obligatory for all of them; each person must undertake to call
people to Islam, according to his ability. However, generally speaking, with
regard to every country, what is required is for there to be a group that is
devoted to the mission of calling people to Allah, may He be glorified and
exalted, throughout the world, to convey the message of Allah and to explain
the command of Allah by all possible means, because the Messenger (blessings
and peace of Allah be upon him) sent out callers, and he sent letters to
people and to kings and rulers, calling them to Allah, may He be glorified
and exalted.

See: Majmoo‘ Fataawa Ibn Baaz, 1/330

Secondly:

There is no need at all for differences as to which work
should take precedence: calling Muslims or calling non-Muslims. The one whom
Allah enables to do any of that should go ahead with it. There are some
Muslims who are good at calling non-Muslims, because Allah has given them
the ability to explain things clearly or to convince people easily, or He
has enabled him to learn the language of the non-Muslims whom he is calling,
or because of the nature of his work, as there are many non-Muslims with
him, or because he travels to their country or because he has a neighbour
who is a non-Muslim, and so on.

In such cases we say to the individual: Go ahead and call
these people with wisdom and beautiful preaching, with clear proof, and with
patience in dealing with them.

See also the answer to question no.
99976 for information on how
to call these people.

And there are some Muslims who are good at calling their
fellow Muslims, because of some of the things that have been mentioned
above; or because he does not have the patience to call non-Muslims; or
because he has skills in convincing and debating in various issues and
establishing clear proof; or because he is well versed in some branches of
Islamic knowledge that may be needed more by one who calls Muslims than one
who calls non-Muslims.

The point of all this is to say that there is no need for
disputes or arguments, let alone division, around this issue. Both are
necessary according to sharee‘ah, and each person will be enabled to do that
for which he was created. The one who finds that he has an interest and is
able to work in either of the two fields should not denounce anyone who
works in the other field, because both of them are good and are necessary,
and neither takes precedence over the other at all. We do not know of any
one among the early daa‘iyahs (callers) who said: We are going to refrain
from calling the non-believers until we have set straight the Muslims’
affairs. When will that ever happen?!

Moreover, we do not know of anyone who says that we should
refrain from calling Muslims, teaching them and setting their affairs
straight in order to focus on calling the non-Muslims and bringing them to
Islam.

There is no room for conflict in da‘wah; rather it is the
task of every Muslim, each according to what he is able to do and what Allah
has given him of knowledge, forbearance, wealth and so on.

See also the answer to question no.
150066,
77579,
164443

And Allah knows best.