There are many reasons to believe God, that is, to believe what He has told us in His precious Word, the Holy Bible.
Here is just one of them.
It's impossible for God to lie. He cannot tell a lie.
Titus 1:2 says, "In hope of eternal life, which God, who cannot lie, promised before time began"
What God is not lying about is hope and eternal life. Rather, He is telling us the truth about it, because He cannot tell a lie.
And, this hope of eternal life which He has promised, is something He promised even before time began.
So, He was not lying then, He is not lying now, He will never lie in the future, and that's no lie. It's the truth.
I'm personally, very, very comforted in this truth about God, because it means that everything He says to me is absolutely true.
There is not even the slightest chance of it not being true.
I can rest in completely what He says, I can trust in Him without any reservation.
P.S to tell a lie, means to intentionally tell a falsehood.
By the way, the Devil can't tell the truth at all, all he does is lie.
Joh 8:44* “You are of your father the
devil, and the desires of your father you want to do. He was a murderer
from the beginning, and does not stand in the truth, because there is no
truth in him. When he speaks a lie, he speaks from his own resources,
for he is a liar and the father of it.
Pastor Bob Grenier