Lowercase truth demands obedience to the objectified world and its "reality" of meaninglessness and purposelessness. It denies spirit and stresses necessity. It considers anything toward which the spirit aspires to be non-existent and everything that crushes the spirit to be omni-existent. Lowercase truth is a forceful master and it demands passive acceptance of its abstractions. It denies all light and claims darkness to be true.
Uppercase Truth is the voice from the Gospel: "I am Truth." It testifies to the meaning and purpose of the Reality of subjects. Truth liberates spirit from necessity. Truth frees. It is everything toward which the spirit aspires and the highest form of existence. Uppercase Truth is a friend requesting active creativity through love. Truth is the light of an integral spirit that exposes the lying darkness of lowercase truth.
Lowercase truth seeks passive slaves.
Uppercase Truth seeks active creators.
As Dostoevsky once noted, if truth is one side, and Christ on the other, it is better to reject truth and go with Christ; that is, it is better to refuse the dead truth of a passive intellect for the sake of the living Truth of the integral spirit.
Note added: The above was inspired by passages from Berdyaev's The Meaning of the Creative Act.