DO WE OBTAIN BY RUNNING, OR BY GOD'S MERCY?

Romans 9:16 So then it is not of him that willeth, nor of him that runneth, but of God that sheweth mercy. (KJV) 1 Corinthians 9:24 Know ye not that they which run in a race run all, but one receiveth the prize? So run, that ye may obtain.(KVJ)

It depends on what is being obtained.  Salvation (the subject of the Romans passage) is given only through the mercy of God.  We either accept it or reject it, but we don't strive to obtain it.  In the Corinthians passage, Paul is speaking of carrying out God's work in spreading the Gospel to others.  To successfully carry out God's work on Earth does take effort on our part.  Not a contradiction.