Read this Hadith, and carefully!
Narrated Abu Huraira:
The Prophet sent some horsemen to Najd and they brought a man called Thumama bin Uthal from Bani Hanifa. They fastened him to one of the pillars of the mosque. The Prophet came and ordered them to release him. He went to a (garden of) date-palms near the mosque, took a bath and entered the mosque again and said, “None has the right to be worshipped but Allah an Muhammad is His Apostle (i.e. he embraced Islam).”
Background: Thumama was a captive. When an enemy is captured, you can basically do anything you want with them. Companions had intended to teach him a lesson, at least. So they tied him up to one of the pillars of the mosque. But Prophet (SAW) released him despite having the upper hand. Seems crazy apparently. But the results prove otherwise.
Seeing Prophet (SAW) character, Thumama accepted Islam. Yes, character was the only reason.
O you who claim to follow the Prophet (SAW), your real job as a Muslim is to BE the best Muslim. Be the best father, the best brother, the best husband, leader, Imaam etc. in light of the Seerah of Muhammad (SAW). When you’re playing your part, you’re automatically inviting people to Islam. This, brothers and sisters, is called silent Da’wah. We all need to get better at this inshaAllah.
Reminds me of a recent talk Nouman Ali Khan gave stressing on the same point:
Ready to be the best? Take out a book on Seerah and start reading!
(Personal favorite is: Muhammad (SAW) his life based on the earliest sources by Martin Lings)