Reasoning can take you a long way. Just look at this community. Being a part of the StackExchange network, a good percentage of the members (including myself) come from a highly technical, scientific background, and would likely revolt at the thought of rationality being incompatible with Christian faith.
The problem is that reasoning is only a process. It's a tool, and like any useful tool, it's susceptible to the golden hammer fallacy, particularly when one fails to realize that the reasoning process does not (and provably can not) provide any foundation to start reasoning from.
Reasoning is the process of taking information and drawing useful conclusions from it through the application of rational rules. As such, it can only ever be as good as the information you start with. For an illustrative demonstration of the significance of this fact, take a look at late medieval science sometime. Stuff like phlogiston theory (an explanation of how fire works in the absence of atomic theory and an understanding of oxygen) or retrograde motion (an explanation for peculiarities observed in the orbits of our neighbors in the solar system, based on a geocentric model instead of a heliocentric one.)
The people who studied this stuff did a lot of very interesting experiments, which were valid according to the scientific method, to try to figure out how things really work. But because they began with incorrect assumptions, they reached bad conclusions. Reasoning was useless in these cases; what was needed was better data. (And indeed, when better data became available, scientists were able to reason out more accurate theories pretty quickly, and the old ones became obsolete.)
This is where faith comes in. God has given us everything we need to have a reason to believe that he exists, but he stops short of providing absolute and universal proof because that would interfere with the development of our faith, and salvation comes only through faith. (The reason why it's only through faith that we can be saved is a matter for another question, and not everyone agrees on the details, but the fact that it's necessary is nearly universally accepted as Christian doctrine AFAIK.) So your parents and friends are right, to a point. You can't find God through reason alone. But when you have achieved a foundation of faith, it's certainly possible to use reason to strengthen your faith, or to figure out how to deal with problems in our lives when no obvious, explicit solution is given in the scriptures.
God has revealed his existence, his plan for us, and the rules that we need to live by in order to find happiness in this life and salvation after this life, through his prophets and apostles. This information has been recorded in the scriptures, to preserve it for later generations, like us. If we can exercise our faith enough to accept this, it gives us a solid foundation to start reasoning from when it comes to many important aspects of our lives. For example, we're told that Paul made a habit of using the scriptures which the Jews had already accepted to reason with them and help them find faith in Christ, (Acts 17: 1-3, see also Acts 18,) and that the resurrected Lord did the same with two disciples on the road to Emmaus. (Luke 24: 13-25)
So no, there's nothing wrong with using reason to increase your faith. But it cannot establish your faith, and it should not be the only thing you allow to guide you. There are times when we reach the limits of what we know, and reason becomes useless. In those cases, it's necessary to simply let God's word serve as a lamp unto our feet, lighting
our path one step at a time, and walk by faith, not by sight. Having both principles available to you will make you stronger than having to rely on only one or the other, particularly if you can learn when the appropriate time to apply each of them is.
