What is the correct method of da'wah to the youth?

Question:
Some of the youth were approached, advised, and directed to call to the tawhid (the oneness of Allah) of Allah (Glorified and Exalted is He), but they became angry, sad, and their hearts were filled with distress toward us. So, may Allah preserve you, do we remain with them or leave them?

Answer:
They are taught and advised, for tawhid is the first priority. If the Muslims are upon tawhid, they are taught what they do not know regarding their prayer and their fasting.
As for if they are among people who have shirk (associating partners with Allah), they begin with tawhid, teaching them tawhid first; because deeds are not valid except after being safe from shirk.
As for if they are like this Saudi community or its like—in a good Islamic community—they call them to what they think they have fallen short in, or what is hidden from them, and they alert them to it if they are people of tawhid. They alert them to the things that are hidden from them: in their prayer, in their fasting, in their zakah (the obligatory alms), in their Hajj (the major pilgrimage), and in their transactions. But if they are among disbelievers, they begin with tawhid and warn them against shirk.
Q: ... They say: You are frightening us and frightening others?
A: The call to tawhid is not frightening if it is in a community that has shirk. This is how the Prophets called; they began with the call to tawhid. So the Messenger (peace and blessings be upon him) began with the call to tawhid, and he remained for ten years, all of it being a call to tawhid, before the prayer was made obligatory.