Note 9 at 1Co 16:22: The word "ANATHEMA" means "accursed" (Vine's Expository Dictionary), and the words "MARAN ATHA" mean "our Lord has come" (Strong's Concordance). So, Paul was saying, "If anyone doth not dearly love the Lord, Let him be anathema (that is, 'accursed'): Maran atha (that is, 'The Lord cometh')" ("The Emphasised New Testament" by J.B. Rotherham).

Because of Paul's instruction in Ro 12:14, which says, "Bless them which persecute you: bless, and curse not," it is certain that Paul was not violating his own instructions. He probably was stating that those who do not love the Lord are already under the curse, as John wrote in Joh 3:36 (see note 4 at that verse).