In the Christmas story, the wise men bring gifts to the Lord: gold, frankincense and myrrh.

The gold is listed first, because it is the inmost - signifying good, e.g. the good that we do when we love the Lord and the neighbor.

The frankincense is next. It signifies rational truth, which is the set of true ideas that we know, not about external things like cars or cooking, but about what is really good, and what is really true.

These rational truths are built on earlier knowledges that we learn, before we have really made them our own. Those early knowledges about spiritual things - often learned in childhood - are represented by the myrrh.

In a way, these gifts are really a reciprocation. We can't actually give them to the Lord until the Lord has given them to us. We necessarily start out by learning and doing the Lord's law (myrrh). The Lord can then call up those memories to become rational truths (frankincense). Then, over time, and with effort, those truths can be transformed into good (gold). The wise men from the East had gone through this process of learning and becoming vessels that could receive truths and goods. They were able to perceive the Lord's birth, and find him, and bring gifts to him.

In Genesis 37:25, 'spices, resin, and myrrh' signify interior natural truths joined to good in the natural level. Among the ancients, they used things with sweet smells and fragrance in their sacred worship. This is where their incenses and perfumes came from. Similar things were also mixed in the oils used for anointing. In the present day, it is not known where this ritual originated. This is because we do not know that the things used in ancient worship originate in spiritual and celestial things, in heaven, and correspond to them. People have removed themselves so far from these things, and immerse in natural, worldly, and bodily things, that they are in obscurity, and many in a negativity regarding the existence of anything spiritual and celestial. The basis and reason why the ancients used incenses and perfumes for sacred purposes was because 'odor' corresponds to perception, 'a fragrant odor,' such as spices of various kinds, signify a gracious and pleasant perception, like truth based in good, or faith grounded in charity.

(References: Arcana Coelestia 4748, Genesis 25, 37)