It is used in the Bible. It is only spoken of in Scripture in regards to Christ and our Father. It's "splangchnisomai" in the Greek. It's what we would call guts.
Think about this for a moment. When Christ was moved with compassion it was like he got kicked in the gut.
How did Christ feel? Did he feel pain in the deepest part of Him, a pain that caused him to bend?
As Christians, we feel compassion as Christ did, struck in the stomach, kicked in the gut, pain in the deepest place. This pain causes us to reach down, reach out to others, becoming cruciformed, shaped into the cross of Christ.
Compassion isn't a vague sense - it's a feeling so strong that is causes you to bend; it shapes your body, your life, into a response. You give, you learn, you change, you are conformed more to Him.
God is with us as we give. The God of Compassion is the God who is with us, the Word made flesh that dwelt among us and continues to dwell in us.
In Latin, compassion is 'pati' and 'cum'. It means 'to suffer with'. Compassion chooses to suffer with the sick, to be kicked in the gut, to weep with those suffering, to pray with those powerless, to cry with those cast out. Compassion is the condition of being fully human and fully Christ-like and being fully with.
In Hebrew, compassion is similar to the Greek. It's 'rachamim' - meaning bowels, a tender love, and that 'rachamim' derives from the word 'rechem'
which means womb.
Christ followers are always safe in God's womb. We move within the womb of God.
Our God is both Father, mother and His body is our brother and sister stirred in the deepest places, suffering with others. The Compassion of Christ shakes the earth to respond, to labor and deliver with Him a new Kingdom.
We are to bring into the world the endless, streaming amazon of God's tender compassions, His mercies, His inexhaustible, Christ-made grace.
---be compassionate, just as your Father is compassionate.