The only time I ever really hear about taqwa is at the onset of Ramadan, and throughout that month. That's because taqwa is supposed to be the reason Muslims fast--to acquire taqwa, to become muttaqeen (i.e., people who have taqwa, or people who are conscious of Allah.) So let me first review a description of taqwa that I have found, as I grow in Islam, to be a truly beneficial aid to understanding this concept.
'Umar bin al-Khattab asked Ibn Ka'ab for the definition of Taqwa. Ibn Ka'ab asked 'Umar how he would traverse a thorny path. 'Umar said he would carefully walk, gathering his clothes so they would not get stuck on the thorns and hence causing him injury. Ibn K'aab said "This is the definition of taqwa, to protect oneself from sin through life's dangerous journey so that one can successfully completey the journey unscathed by sin."
Now, I heard this description before my first Ramadan, and to be quite honest I didn't really understand it at all. But I wrote it down, to think about. Now let me tell a story to explain how it applies to da'wah.
There was a new Muslim sister who was eager to share her faith with the world. Browsing some blogs, she came across a man who had acquired an interest in Islam, and though he had emailed a local imam, he never received a response to her questions about Islam. So the new sister, wanting to reach out and give the man some da'wah, answered his questions, which he had posted on his blog, leaving a link to her blog. Appreciatively, the man followed her back and through what she had published he was able to learn her story about accepting Islam, and her reflections on how it now applied to her life. That intrigued him even more but he also became interested in the new sister, and began a correspondence with her to ask her questions about Islam.
Through that communication, the two became close friends--closer than was appropriate. The man shortly embraced Islam, and made his romantic inclinations clear to the girl, who through the process of teaching him about Islam, had also developed a friendship she thought significant. Because the sister had been trying to get married, the new brother began suggesting that he would make her a good husband and pressured her to meet, offline. The communication which had first been email, then instant messaging, then phone calls, escalated to a meeting in person. With neither particularly familiar or concerned with the Islamic etiquette of courtship, the two met alone. The sister, with no wali or even any friends in her Muslim community, agreed to meet with the brother very new to the faith who was beginning to seem much more concerned only with the sister than with Islam at all.
There are a few obvious problems with the scene--the couple being alone, the sister especially without anyone to watch out for her interests, and even the brother's conversion coinciding with an increase in romantic feelings for the sister.
Alhamdulillah, Allah saved her from further sin, and the sister managed to keep her Islam in tact although the brother apostated shortly thereafter.
I think this is a sad story, because it represents a real failure of da'wah (demonstrated by the apostasy) and also a comprising situation for new converts, who could not be alone except that Shaytaan would be among them.
Now maybe you're thinking about these two concepts--the description of taqwa, and the story--and wondering how they are related? So let me explain. When giving da'wah, having taqwa is absolutely essential (along with sincerity (ikhlaas), and mercy (rahma), and knowledge (ilm)) because this is what happens. Shaytaan, the avowed enemy of every Muslim, will try anything he can to lead a person astray. Which means, he might even try to convince them to give da'wah... or rather, use the excuse of da'wah to lead them to a compromising situation. And this is why scholars rightly caution men and women both against giving personal da'wah to someone of the opposite sex. Because Shaytaan will use the opportunity very swiftly to lay a trap.
But if a person has taqwa, and he is walking the path while trying to keep his clothes from getting snagged, he will stay away from this trap, seeing that it is a trap. And he will see that even though there is an opportunity for goodness (through the da'wah), that there is also a very dangerous opportunity for harm.
So what is the solution, in an example like the story? Da'wah is good, and if a person shows interest in Islam it is always good to give them some information, right? But if the person is someone whom you could marry (so this doesn't apply to siblings), the better approach is to acquaint the seeker with another Muslim of their same sex, who you trust to convey the message of Islam.
This is a gentle reminder to myself above all, and everyone else who might be interested in giving da'wah.