How Propaganda Messenger with Weak Gentle and Love

Prophet Muhammad was the one who most understands da'wah. So, do we have da'wah permission? The answer is no, but our da'wah just ride to the Messenger of Allah.
Allah ta'ala said to the Messenger of Allah, "say, this is my way". It invites people to Allah swt. Instead of inviting people to their own lusts and worldly aims.
Someone says "Invite people to your Lord with wisdom wal mauidhah hasanah!".
It is not the method of propagation of the Messenger of Allah. We need to take sanad to the Prophet in scholarship, understanding of science, and in the method of da'wah. We must follow the Messenger of Allah.
There is nothing in vain on good words, nor is there a goodness in painful words. When one speaks good words, it is reminiscent of the Messenger of Allah. "Oh, this is what the Prophet used to be". Or when we cursed, "Oh, so the Messenger of God is also a liar?". That is, someone will assume about Islam, just because who delivered it. So, be someone who hums Islam well.

We are commanded to guard the tongue. Do not swear! do not make a mess of a people! Do not think differently between people. Do not also denounce it because of the difference.
Because there are errors that should not be faced hard, while a gentle solution can still be done.
What is done by sinners, penista, criminals, it is evil, certainly a sin. However, when we cursed and scolded, it was a sin. When it comes to granting and hunting, it is also a sin.