“Thou shalt love the Lord thy God with thy whole heart, and with thy whole soul, and with thy whole mind. This is the greatest and the first commandment. And the second is like to this: Thou shalt love thy neighbour as thyself.”
Gospel of Matthew 22:37-39.
This teaching of Jesus from Saint Matthew’s Gospel reminds us of the Cross.
The love of God is the vertical part of the Cross,
while the horizontal beam represents the love of neighbour.
Both the vertical and the horizontal form The Holy Cross.
Without the vertical piece (the love of God) one is left with just a sign.