we can never tell when someone is being nice to us either loves us or not.
But for someone to observe it from a distant can tell.
Why is he being nice to you all the time?
when you go to class/church/school, would he always be the first to stay hello to you?
would he offer to pay for something or buy you something?
would he keep talking to you? and give you all attention you need?
to makes things easier, why don't you simply ask him?
"do you like me?"
or
"how much do you like me?"
or
"what do you think of our friendship?"
but then again, when you have a best friend, they will stay loyal to you and treat your like a partner or brother/sister, ones who can't experience the relationship of best friends would think something is going on between you two.
My best advice is not to make assumptions but to take action and ask.
You might not know, he may love you and tried so many ways to hint that he loves you, but you couldn't care.
When you finally develop a feeling for him and you want to show him your feeling, that might be when he finds someone else:/
so catch the fish opportunity before it's too late.