1) Every truth leads to another one. Otherwise, truth's limit would be a non-truth, in which truth is going to find its beginning and its end. In that case, false propositions would proceed to true ones, and true ones would generate false ones as well.
2) Thus, every truth, whatever it may be, guides us by means of an infinite enchainment to supreme and unattainable Truth, which is God.
3) By stating a single true proposition, being really true, we are denying the limit that will denaturalize it (vid. 1); we are declaring an infinite progression of truths and, consequently, recognizing God's existence (vid. 2).
4) So, even if that hypothetical true proposition was "God doesn't exist", as far as it is asserted as a truth (vid. 3), it follows that God (i.e. the Truth, vid. 2) exists.
5) However, if God exists, the previous proposition (vid. 4) is false; and, if God doesn't exist, it is false too, because in that case the Truth (i.e. God, vid. 2) wouldn't exist and, then, single truths wouldn't exist either (vid. 3). So, in any case, God exists.
Greetings.
Daniel.
Theological Miscellany (in spanish):
http://www.gratisweb.com/irichc/MT.htm