Do not stop calling non-Muslims to Islam for fear that they may revile the religion
Question

I am involved in calling people to Islam (da’wah) via chat rooms, Paltalk and Messenger. I call Muslims and non-Muslims. My question is: sometimes I want to call a person who is not Muslim, but I am afraid that if I call him, he may revile Islam. Should I refrain from calling him? If I must do that, then I should not call any non-Muslims, because I am afraid of most of them, because I do not know them. What do you advise me to do?.
Praise be to Allah.Firstly: 
We ask Allah to increase your energy and guide your efforts, and grant you the best of rewards for your interest in da’wah and calling people to the religion and way of Allah. There is no one who is better in speech and conduct than one who guides the people to truth and light. 
Allah says (interpretation of the meaning):
“And who is better in speech than he who [says: ‘My Lord is Allah (believes in His Oneness),’ and then stands firm (acts upon His Order), and] invites (men) to Allah’s (Islamic Monotheism), and does righteous deeds, and says: ‘I am one of the Muslims’” [Fussilat 41:33]
But I warn you that private chat rooms are a door to temptation and evil, because among those who enter them are women and those who follow their whims and desires. The daa’iyah may begin by talking to everyone, and the shaytaan sets traps of specious arguments and desires, until he instils in his heart the temptation to imitate the followers of falsehood, or he makes him influenced and controlled by haraam desires, then he plays with him as a child plays with a ball. Allah says (interpretation of the meaning): 
“And (remember) when Shaytaan (Satan) made their (evil) deeds seem fair to them and said, ‘No one of mankind can overcome you this day (of the battle of Badr) and verily, I am your neighbour (for each and every help).’ But when the two forces came in sight of each other, he ran away and said ‘Verily, I have nothing to do with you. Verily, I see what you see not. Verily, I fear Allah for Allah is Severe in punishment’” [Al-Anfaal 8:48]
On our site we have previously offered advice to those who engage in da’wah via the internet, lest the shaytaan ensnare them in ways they did not imagine. We have stated that public da’wah or organizing da’wah efforts in this field should be done by organizations or groups, and this is more beneficial and safer than individual efforts, because the shaytaan is closer to the one who is alone. 
See question no. 32693. 
Secondly: 
The one who wants to call others to Allah must equip himself with the shar’i knowledge that he wants to convey to others, and he should have sufficient experience to debate well with others, and he should have some knowledge of the doubts and desires that they suffer from, and how they may be treated. If all a person has is sincere emotions and a little knowledge gathered from here and there, that will not achieve anything and it will not benefit the one whom he is calling at all. The worst thing that we fear for the one who embarks on such a mission before he is prepared for it and before he is properly qualified for it, is that he may be like the one who is overcome with compassion for the people who were stricken with a fatal disease and he rushed to help them without any experience in medicine, so he does not benefit the sick or protect himself. There is a saying; “He went hunting but he got caught.”  So beware, O slave of Allah, and let your first concern be to save yourself. 
“Nay! Man will be a witness against himself [as his body parts (skin, hands, legs) will speak about his deeds],
15. Though he may put forth his excuses (to cover his evil deeds)” [al-Qiyaamah 75:14-15]
Thirdly: 
If a person is qualified to call people to Allah, no matter in which field he works to call them, it is not permissible for him to stop calling on the basis of fear that a person may reject the call and insult the message or the religion, otherwise there would be no more da’wah and no one to explain the true religion to people. This is not what pleases the Lord of the Worlds. Rather Allah has commanded us to adhere to wisdom and use beautiful preaching. Allah says (interpretation of the meaning): 
“Invite (mankind, O Muhammad ) to the way of your Lord (i.e. Islam) with wisdom (i.e. with the Divine Revelation and the Quran) and fair preaching, and argue with them in a way that is better. Truly, your Lord knows best who has gone astray from His path, and He is the Best Aware of those who are guided” [al-Nahl 16:125]
The Messenger of Allah (peace and blessings of Allah be upon him) urged us to be kind and gentle, giving glad tidings and using an easy-going attitude, out of keenness that the people who are called should accept the truth that is presented to them. 
The Prophet (peace and blessings of Allah be upon him) said to Mu’aadh and Abu Moosa when he sent them to the people of the Book in Yemen: “Be easy going and do not be harsh, give glad tidings and do not put people off.” Narrated by al-Bukhari (3038) and Muslim (1773). 
The one who adheres to this method of calling people will not be harmed if the one whom he calls turns out to be one who reviles the religion or rejects it or is arrogant towards it. 
The leader of the daa’yahs, the Prophet (peace and blessings of Allah be upon him), was continually involved in calling people to Allah and offering wise advice, even though many of the mushrikeen responded with insults, beatings and mockery. 
It was narrated that Ibn ‘Abbas (may Allah be pleased with him) said: 
When the words “And warn your tribe (O Muhammad) of near kindred” [al-Shu’ara’ 26:214] were revealed, the Messenger of Allah (peace and blessings of Allah be upon him) went out and climbed al-Safa, then he called out: “Ya sabaahaah (Be on your guard)!” They said: Who is this that is calling out? They said: Muhammad. They gathered around him, and he said: “O Banu So and so! O Banu So and so! O Banu ‘Abd Manaaf! O Banu ‘Abd al-Muttalib!” They gathered around him and he said: “Do you think that if I told you that there was a cavalry emerging from the foot of this mountain, would you believe me?” They said: We have never known you to be a liar. He (peace and blessings of Allah be upon him) said: “I am a warner to you of an imminent and severe punishment.” 
Abu Lahab said: May you perish! Did you call us together only for this? Then he stood up, and this soorah was revealed: “Perish the two hands of Abu Lahab (an uncle of the Prophet) and perish he!” [al-Masad 111:1]. 
Narrated by al-Bukhari (1394) and Muslim (208).
 What is forbidden is initiating insults and put-downs with the mushrikeen and kuffaar, lest that make them respond in like manner. This is what Allah forbids in the Quran. Allah says (interpretation of the meaning): 
“And insult not those whom they (disbelievers) worship besides Allah, lest they insult Allah wrongfully without knowledge” [al-An’aam 6:108]
Do not feel ashamed of the truth, and do not give up conveying the message of this religion with knowledge and insight. Strive to choose appropriate words and choose the right approach. Avoid insulting and mocking, and all kinds of wrongdoing and aggression, then after that it will not matter whatever the person you are calling may say. His sin is his burden to bear on the Day of Resurrection, and you will earn reward in sha Allah. 
And Allah knows best.