"Will you do the honour and be my wife?"
Jace was down on one knee. He had been planning this for weeks, the perfect proposal was impossible to be free from oblivion. He wanted the proposal to be remembered. Oblivion. Oblivion- means forgetting- was possible.
He was proposing right in the middle of the institute weapons room. This may sound reckless to any one else, but it was where jace held his most prized possessions. His way of showing clary she was his medal. He won her through mental and physical battle. He loved her more than all the weapons in the world.
A weapon can defend you from some kinds of danger. But you need a person dominating the weapon to fulfil the purpose of the weapon. When you have a person who cares for you so much- and vice versa- then that is all you need to conquer evil.
You need a soul.
A soul hat understands you.
Love conquers all.