Let me be absolutely clear:
Titus 1:2 επ ελπιδι ζωης αιωνιουην επηγγειλατο** ο αψευδης θεος** προ χρονων αιωνιων
Titus 1:2 … had promised, the unlying God, before times eternal.
Many English translations will correctly state, “God who can’t lie, has promised”
Or again; The Latin states:
Titus 1:2 in spem vitæ æternæ, quam promisit
qui non mentitur, Deus, ante tempora sæcularia :
Who cannot decieve;
en.wiktionary.org/wiki/non#Latin
Notice the verb ending in the example is the same, the phrase is identical with “deceive” being replaced with “read”.
In neither example is a verb of “being” added, It isn’t “God
does not lie.”, rather it is his very name – God, Unlying. Or God who can not lie.
To make the point very strongly, Jesus doesn’t merely say “I don’t lie”, rather he says something stronger:
John 14:6 Jesus saith to him:
I am the way, and
the truth, and the life. No man cometh to the Father, but by me.
In Genesis, God “said” and it was. The word, by being spoken, causes creation to happen – out of nothing, by raw power. The very same power makes it impossible for God to lie, for the very reason that if he opened his mouth to actually speak it – the very act would make it “be”.
This is a deep mystery. One that Job gets a partial answer to in the end – existence itself requires the problem of evil. Two mutually exclusive things (contradiction) are not in God; evil and Good; In God is
only Good, and only God
is good. There is no shadow, no hint of evil in God himself. His name is “Good” and his name is “God”, these are synonymous. And therefore, evil’s very existence is not created by him – and he can’t create evil itself.
Rather, evil is when someone relatively perfect, as was Adam, who can stay in union with God – chooses to break his friendship with God; wanting to be perfect without the source of perfection; and therefore, he no longer is told the answers by God – but is left to his own ignorance and inevitably, ignorance itself will lead to multiplication of sins (if not direct culpability).
I don’t agree with saying “God can lie”, but he never will – although I once thought that way; Think about it – what proof would you or anyone offer that God “can” do actual moral evil ? Is it not a guess, a conjecture, a dreaming of power being the ability to sin? Is it not making God in man’s image by insinuating a “possibile” blackness inside God? I don’t think that has any reality.
I hope this helps with Catechism. I don’t fault you for wanting to defend God’s power – but I think it more important to defend his ultimate Goodness in an apologetic setting.
–Peace.