How can one acquire good character, and is it incumbent upon him to be patient with the wrongdoer out of forbearance, or to retaliate in kind, in accordance with the noble verse: "And those who, when tyranny strikes them, they يَنتَصِرُون (help themselves/defend themselves)"? And when is a gentle or strict approach appropriate in Da‘wah (inviting to Islam)?

The fundamental principle in proselytization (da'wah) and interaction is gentleness, leniency, and forgiveness, for it adorns and does not tarnish. However, if there is a preponderant benefit in severity or withholding forgiveness—meaning the person does not benefit from leniency—then what is more expedient should be done. So, if forgiveness leads to rectification, it is better; but if it leads to corruption, then it is impermissible. If the matter oscillates between the two, the side of forgiveness should prevail. This requires insight and experience, which are attained by seeking Allah's help and by observing people's behavior.