. . . What reason do I have to believe Christians as opposed to Muslims?
Simply hearing about something is not enough.
Agreed.

It is not enough.
To be a Christian is more than holding to a set of ideas.
It is a way of life. It involves one totally.
The reading and contemplation of recorded revealed truths is one aspect.
A more important one is the actualization of these ideas in daily life.
One cannot simply think about the nature of God; the point is to do His will.
As one becomes a more loving person, it becomes clearer what is love.
Along with this comes an awareness of that which keeps us from our goal.
You may wish to consider your motives for being here.
How pure are they? To what degree do they manifest goodness. Do they speak to the awesomeness and beauty of life? To the truth?
Where this fails, is where I would see sin.
Imagine Satan as sin, evil, death and suffering personified.
Imagine that the converse is true, that rather than personifying a blind force, the reality is that some sort of person has led us to this predicament.
That person has been conquered but we remain in this state. We do however, have the means to be pulled out.
This gets complicated. I’m not asking you to believe what I am saying. What the world needs is greater understanding of one another, if we are to grow.