Alma 41:14

"Therefore, my son, see that you are merciful unto your brethren; deal justly, judge righteously, and do good continually; and if ye do all these things then shall ye receive your reward; yea, ye shall have mercy restored unto you again; ye shall have justice restored unto you again; ye shall have a righteous judgement restored unto you again; and ye shall have good rewarded unto you again."

This makes sense.  If you are merciful, just, righteous, and do good then you will receive those things again.  It may not happen on this life, but God will reward you for your goodness. Treat others how you want to be treated.