Do you have a life verse? Many people do. Should you pray for a life verse? I know someone who likes to joke about this by saying, "The Bible is my life Scripture." I think that is funny, but it does not really grasp what a life verse is and does.
First, the concept of a life verse is based on the conviction that God speaks to us personally. This is certainly taught in the Bible. From Adam and Eve in the Garden to John on Patmos, from Elijah hearing His still small voice to the disciples hearing the voice out of the cloud on the mountain top, God speaks. Many people seek the Scripture for truth and life principles. And we certainly find principles in Scripture, but we also need direct personal communication with God.
The words "life verse" are not found in Scripture, but we certainly see God speaking to people through scriptures. A good example is found in Acts 13. In verse 47 Paul and Barnabas said, "This is what the Lord has commanded us." And then they quoted from Isaiah 49. "I have made you a light for the gentiles, to bring salvation to the ends of the earth."
Of course without a life verse you can believe God speaks and even experience Him speaking to you day by day as you read the Bible. In fact the Bible teaches that if you understand Scripture God is speaking to you. 2 Corinthians 2:14 says the things of God are spiritually discerned or understood.
However, it is possible for God to speak a life-long message to a person. That is what Paul and Barnabas were declaring in Acts 13:47. Of course God can speak to people any way He chooses. I believe God sometimes speaks through His silence. I love the statement from Experiencing God. "God speaks through the Bible, prayer, circumstances and the church to reveal Himself, His purposes and His ways."
So, should you pray for a life verse? I do not know. God may be prompting you to pray for such a verse. But how God speaks to you is God's business. I would urge you to be open for God to give you a life verse as He speaks to you in Scripture. In fact, I believe you need to be open for God to give you more than one lifelong word. I have six life verses. I have them memorized and I pray over them every day as I begin my devotional time. God of course still speaks to me in Scripture and in other ways encouraging, directing, strengthening, teaching or warning me.
Interestingly enough, my wife and I also have scriptures that we believe God has led us to in praying for other people, especially family members. These passages inform our prayers and encourage our faith as we lift them up to our Heavenly Father. Life verses and similar uses of the Scriptures help us pray the word of God.