Proverbs 19:8 He that getteth wisdom loveth his own soul: he that keepeth understanding shall find good.
Every person loves himself, is essentially self-centered, looks out for his own interest interests. This is a given fact of human nature, for every human is a born sinner, in the likeness of Adam. When Jesus summarizes the Law with the command he assumes this to be true: “Love your neighbor as yourself.” Even people with low self-esteem who hate themselves do so precisely because they love themselves.
This proverb says that if you really do love yourself (and you do) then you should want to “get wisdom.” Wisdom is good for you, and the promise is that you will find good. The “if” condition for the promise is getting wisdom and keeping understanding. This is the same thing as believing Jesus and staying in that faith. When you believing in Jesus you have found good. You have eternal life and countless gifts, promises, and blessings that come with it.
Faith in Christ brings in the Holy Spirit, who grants faith through the Gospel of Christ. 1 Corinthians 1:30: “And because of him you are in Christ Jesus, who became to us wisdom from God.” Christ is wisdom. Believing in Him is getting wisdom, and that is an unbelievably good thing to do. And the further condition and promise is that He (the Spirit) will keep understanding. I believe that the HS has “called me by the gospel, enlightened me with his gifts, and kept me in the one true faith.”
Keep the faith, and you, who love your soul, have found good. That is, the good God has found you. Thus, the best thing you can do for yourself is hear the word of Christ and keep it. You are blessed, and you have found something good.