The second statement seems more in line with the way 'true' was used to explain 'religious truth' in the Religious Studies section on the BBC GCSE Bitesize website.
Also, the second statement seems more useful to the individual - unless a person thinks that their belief is true, what would motivate them to act on their belief?
No the second statement implies an objective truth, which cannot be sustained without evidence, and that isn't compatible with a subjective opinion or belief.
The first statement is fine, but lacks any relevance as it is simply countered by someone else having an alternative view, namely:
'It is the truth that I do not believe that Jesus is the son of god'
The second statement is unsustainable as whether or not Jesus is the son of god is not a matter or subjective belief but is either objectively true or not objectively true.
Let's use a different - and less contentious example. Rather than 'Jesus is the son of god' let's use ' the earth is flat'.
So we now have:
'It is the truth that I believe that the earth is flat'
And
'My belief that the earth is flat is the truth'
Only the first statement is sustainable (albeit wrong) as the truth refers to the belief, a subjective notion. The second is not sustainable as the truth relates to the shape of the earth - an objective truth, not one determined by subjective belief. The earth is either flat, or it isn't and no amount of belief one way or the other will change that objective truth.