The number "two" has two different meanings in the Bible. In most cases "two" indicates a joining together or unification. This is easy to see if we consider the conflicts we tend to have between our "hearts" and our "heads" -- between what we want and what we know. Our "hearts" tell us that we want pie with ice cream for dinner; our "heads" tell us we should have grilled chicken and salad. If we can bring those two together and actually want what's good for us, we'll be pretty happy. We're built that way -- with our emotions balanced against our intellect -- because the Lord is built that way. His essence is love itself, or Divine Love, the source of all caring, emotion and energy. It is expressed as Divine Wisdom, which gives form to that love and puts it to work, and is the source of all knowledge and reasoning. In His case the two aspects are always in conjunction, always in harmony. It's easy also to see how that duality is reflected throughout creation: plants and animals, food and drink, silver and gold. Most importantly, it's reflected in the two genders, with women representing love and men representing wisdom. That's the underlying reason why conjunction in marriage is such a holy thing. So when "two" is used in the Bible to indicate some sort of pairing or unity, it means a joining together. In rare cases, however, "two" is used more purely as a number. In these cases it stands for a profane or unholy state that comes before a holy one. This is because "three" represents a state of holiness and completion (Jesus, for instance, rose from the tomb on the third day), and "two" represents the state just before it.

36. People who have separated faith from love do not even know what faith is. When they do entertain an idea about faith, some of them see it only as mere thought, others as thought directed towards the Lord, and a few as the doctrine of faith. But faith involves not only knowledge of all the things that the doctrine of faith embraces and the acknowledgment of them; it is first and foremost obedience to everything that doctrine teaches. The primary point that it teaches for men's obedience is love of the Lord and love of the neighbour. Whoever is devoid of this is devoid of faith, a point which the Lord teaches so plainly in Mark as to leave absolutely no room for doubt,

The first of all the commandments is, Hear, O Israel, the Lord our God is one Lord. Therefore you shall love the Lord your God with all your heart, and with all your soul, and with all your mind, and with all your strength. This is the first commandment. The second is also like it, You shall love your neighbour as yourself. There is no other commandment greater than these. Mark 11:28-33.

In Matthew, He calls the former 'the first and great commandment', and says 'on these commandments the Law and Prophets depend', Matthew 22:35-40. The Law and the Prophets are the doctrine of faith in its entirety and the whole of the Word.