Paul's writes again to the church in Corinth. There is evidence that Paul may have written two other letters to Corinth that are not part of the Bible. The other letters are referred to in I Corinthians 5:9 and II Corinthians 2:4. Paul was an inspired writer but that does not mean every single thing he wrote was God inspired and should have been canonized in the Bible. Paul probably wrote to his Mother at some point. That doesn't mean it should be in the Bible, so don't be surprised if a book is mentioned but not included in the Bible. 2 Corinthians was an instructional letter based on things Paul had heard from Titus, (II Corinthians 7:5-7). This book was written in 55 A.D.
In the first seven chapters of this letter, Paul explains why he has been behaving toward the Corinthians the way he has. Please read these chapters at this time.
What did Paul mean when he said, "Do not be bound together with unbelievers;" (II Corinthians 6:14)? Several translations use the phrase "unequally yoked with unbelievers." A yoke was an instrument used to harness two animals together for a purpose like pulling a plow. Since marriage is the closest relationship between people, this passage refers at least to that relationship and perhaps others. Christians should marry Christians. If you are not married, plan to marry a believer if and when the time comes. It would be wise to date believers since you wind up marrying someone you have been dating. If you are married already, then follow what the Bible teaches on what you as a Christian should do to have a strong marriage. The Bible teaches us how to have a good marriage. God wants you to avoid the hardships caused by being unequally yoked. Marriage is holy and precious. Let God guide your marriage.
Keep up the daily habit of your prayer list. Do not forget to update it and spend quality time talking with your heavenly Father.