Oil -- typically olive oil -- symbolizes the good that comes from celestial love. Celestial love is love of the Lord, the highest and purest love we can have. The good of celestial love is the desire to be good springing from celestial love: Wanting to do the Lord's will because you love Him. That's not a state many reach, even in heaven, but it's a beautiful goal. This representation makes sense based on the idea that the sun -- the source of all natural light and heat, and thus all natural life -- represents the Lord, the source of all spiritual light, heat and life. Burning oil was the most pure fire available in Biblical times, thus the closest representation of the sun people could create.

92. None but the person who is acquainted with the state of peace is capable of knowing about the serenity of the peace of the external man, which ensues when conflict, the unrest caused by evil desires and by falsities, comes to an end. That state is so joyful that it transcends every idea of joy. It is not just an end of conflict; it is also life coming from an inward peace, influencing the external man in a way that defies description. At that point truths of faith and goods of love are born, which draw their life from the joy that peace brings.