Of course the question of the thread is:
which of these is right? can He or can He not lie?
The originator's point being that since elsewhere in the Bible God is called Almighty (omnipotent), it should be possible for God to lie. He feels the verse in Titus contradicts that notion.
IMO, he is reading more into the Bible than is there.
Omnipotence/Almighty mentioned in Revelation 19:6 and elsewhere deals with authority, not ability. Great power, great importance.
In Titus 1:2, I don't think our English word "cannot" is a good choice. The word
apseuds implies truthfulness, not inability to lie. IOW, just because one doesn't lie, doesn't mean one is incapable of lying.
So omnipotence has nothing to do with whether one is capable of lying or not and apseuds isn't implying inability to lie.
We know God is capable of lying, so the next question would be, did the Bible writers show God lying or deceiving anyone in the Bible?