"And while the object of faith is not logical, faith itself is an evolutionary byproduct that is itself constrained by logic. Everything in this universe is constrained by a logical model." Alexander Ross, in Facebook group (six degrees of separation) asks for one logical reason to believe in God.
The "constraining" element by definition would be something which is outside of our understanding.
Now we can address the realm of faith. For just as science attempts to create logical models for physics and biology and language attempts to create logical models for communication, so does theology attempt to create logical models for faith. (Remember also that science cannot address origins because it is outside of its realm of measurability.) So what many attempt to do is create a logical model for faith based on the "constrained" assumptions of science - and arrive at no solution. If we begin with the "constrained" assumptions of theology, we are at least comparing apples to apples.
So what are the theological assumptions we can begin with? One, it is necessary to have this discussion in the first place. Two, there is a problem with the world which is called by various names though it is really the same thing: deception, pride, selfishness, abuse, corruption, evil, sin. Three, there are many who claim that they have found the answer to this problem but have either proved themselves false or have been proven insufficient for the need. Four, there should be one solution which is universal and timeless, which by its existence negates all other options (and being TRUE would be forever intolerant). Five, if a solution to the problem exists, it must come from beyond or above the material world and the knowledge contained in it in order to triumph over it for the good of all.
These theological assumptions lead us to the realm of faith. Faith in what or Who does make a difference because it will lead us to think and act in specific ways. If you believe that there is no God, then you will act as if nothing we do or say has any ultimate value or meaning. If you believe that there are many gods (like the pantheistic Greeks) you may behave as if you are a god yourself, which is nearly the same as believing there is no God at all. If you believe that there are many gods (like primitive tribes), you will forever live in fear of the possibility of offending one of them. If you believe in the god of Islaam, you will (among other things) follow Mohammed's example (scary!) If you believe in the Christian God, you should act as if each person is a sinner fallen short of God's glory and are equal in the need for pardon and a restored relationship with Him. This last has proven to be the effective solution to the issue in assumption #2 (above).
It is interesting to note that every person and group falls on one of two sides: truth seekers and truth suppressors. Truth seekers tend to believe that they are finite and cannot claim to know everything but are interested in learning and the promotion of learning. Truth suppressors tend to claim that they know in order to gain personal, political or even religious power.
But all this talk is silly when we compare it to real people of faith! Take a look at what is happening to those who believe around the world at persecution.com and try to tell them that God does not exist!