Good pick up on the word apologetic. It is a technical word, often misunderstood. You’re right, it does not mean an humble and contrite posture, feeling sorry for what we believe, such as we ordinarily might take it to mean. It means something very specific and good. Tillich uses these old words and this is the value of knowing his work, because you actually learn the language of the art.

Apologetics is the approach of entering into the discussion of non-believers WHERE THEY ARE rather than, as in Dogmatics (Barth), making non-believers discuss only in your terms. The Greek root means being strong and fearless in discussion before anyone from the basis of universal reason.  In apologetics, we talk with people from where they are and help them forward from there rather than laying something on them and expecting them to accept or reject it.  And all through appeal to universal reason (logos).

Tillich and I are both apologetic theologians in this sense.  All the great ones are, starting with St. Paul.

Theologians tend to become dogmatic — laying things on people — and leave off the apologetic approach. This is wrong at any time. Christianity got strong in Rome because the early father were mostly apologetic theologians, — many were actually entertainers, rhetoricians, as they were called — they entered into discussions from where people were, no matter where they were, and worked them forward from there, appealing to universal reason (Logos). This is actually the TRULY humble approach, where humble does not mean weak but just the opposite, so strong as to fear going nowhere and able to stand on one’s feet and handle affairs no matter what. That is true humility, born of faith in the Everlasting Arms of the Father supporting one.

AMDG