Though it is surely not an answer often every Christian gives, but it is quite evident that upon serious reflection many Christians do not know why they believe in God as they do. Stripped of all the dogmatic components from the Judeo-Christian position and having just a purely naked theistic view, why do you believe in God as such? One interesting answer that I hear is, “I’m not really sure, other than it makes sense.”
Though I respect their answer and would say that there is some truth behind it, the answer is surely lacking in the sense that upon further scrutiny their answer will be cut at its knees. For, to be sure, the coherency of an idea does not stipulate why we should say such a thing actually exists, let alone devote our lives to it. If the utmost and salient of reasons for why you are a Christian stands on the foundation of how applicable the evidence of God is to your own personal understanding then the foundation can clearly be shaking due to the lack of intellectual (1) incompetency, (2) awareness and (3) sloth by virtue of its own worldview.
Clearly, we are called to “always be prepared to give an answer to everyone who asks you to give the reason for the hope that you have”, (1 Peter 3:15, NIV) and let our “conversation be always full of grace, seasoned with salt, so that you may know how to answer everyone” (Col. 4:6, NIV). Above all, “We demolish arguments and every pretension that sets itself up against the knowledge of God, and we take captive every thought to make it obedient to Christ” (2 Cor. 10:5, NIV).
Since, as Christians we have a motivation for truth. This preliminary disposition we have in front of us in light of the grace and evidence also presented to us (conversion, testimony, etc.) will function as our motivation to go out and study the faith, so that we may be able to “demolish arguments and every pretension that sets itself up against the knowledge of God…” Not as an ends in itself, but to “take captive every thought to make it obedient to Christ.”