For those who believe in God, what do prayers mean to you?

Why do you pray? Do you sincerely believe that your prayers can/will be answered?

Do you also believe in destiny and if you do, does the act of praying make a difference or is still valid? By that I mean, if it is God’s will for you to contract a disease, lose your employment, house or loved-one, can any amount of praying reverse that?

Can one pray for or on behalf of someone else? What if that someone else is a non-believer or perhaps someone in a far away land with a different religion and beliefs?

How long must one pray to get what one wants?