Appoint for thyself a teacher and avoid doubt.
“Rabban Gamaliel used to say: Appoint for thyself a teacher, avoid doubt, and do not make a habit of tithing by guesswork.”
Tractate of Avot 1:16
Everyone must find for themselves a wise person who can help show them the way. Additionally, we must love ourselves for who we are and accept our imperfections. To avoid doubt, we must find good spiritual guides. Uncertainty can have a negative effect on our soul. Therefore, we must do everything to reach certitude and steer clear of gross assessments.
Like faith, certainty is knowing, without a doubt, that we are creations of God and that all we experience is good.