Your criteria on the truth is how far the individual practitioner gains the wisdom and discernment.
I would prefer to call it "usefulness" instead of truth, but close enough.
As per your opinion, God is not useful to be taken in to account in exercising the truth.
Correct.
meanwhile Islam and Christians say oppositely, their religion oblige them to focus on the deity as the most centered core teaching.
Most, but not all Christians do in fact understand their religion to
demand a belief in Ibrahim's God. Even among those, there are various and significant disagreements about what the consequences of that belief would be. Islam is not all that different in that respect, although it does emphasize the need for belief even more.
That, to me, shows that such a belief is far less necessary and far less meaningful than either religion likes to admit. They are not alone, either; the Seicho-No-Ie and the Bahai, among others, also greatly overvalue belief in a deity. Their priviliege, I suppose - but that does not make their belief in such a need
correct.
In this case you think you are righter than both religion Islam and Christianity that rely on the God instead of the way you obtain the wisdom.
I label it as the feeling to be true over others.
I agree.