"Some liberal churches don't even believe that Jesus is truly God."  That whole concept was what led up to formulating the Nicene Creed and all that it means in the first Four Ecumenical Councils from 325-451 AD.
The topic discussed at the Council of Nicaea was "Is Jesus truly God?"  That was where it was decided that Jesus was 'of the same substance---one in being with the Father.'  The Greek word [homoousious] was used and we have, since Advent 2011, been using the word 'consubstantial with the Father' [which is an English translation of the Greek term].

On the other side, at the Council of Chalcedon [451], the Church had to accept that Jesus was not only 'one in being with the Father,' but was truly human as well.  Jesus had/has two natures----truly, fully human and truly, fully divine.  Those Christians, who didn't accept that Jesus was truly human, then became the Monophysites---and their church communities still exist today.  Some of them are possibly conservative churches :-)