It’s the looking forward to the Lord Jesus return.
1 Cor 16:22 If any man love not the Lord Jesus Christ, let him be Anathema Maranatha.
What Does Maranatha Mean? Depending on how it’s translated, the phrase “Maranatha” can mean “Our Lord has come,” “Come, Lord!” or “Our Lord is coming.” Scholars have debated which meaning is most accurate, but all are congruent with Paul’s understanding of Christ’s first and second coming, each bringing out a unique aspect of His past, present, or future work.
If we read the phrase as “Our Lord has come,” it is a creedal declaration of what Jesus has done for us in his incarnated birth, earthly life, and sacrificial death on our behalf. It brings to mind the magnificent words of John 1:14-8:
“The Word became flesh and made his dwelling among us. We have seen his glory, the glory of the one and only Son, who came from the Father, full of grace and truth…Out of his fullness we have all received grace in place of grace already given. For the law was given through Moses; grace and truth came through Jesus Christ. No one has ever seen God, but the one and only Son, who is himself God and is in closest relationship with the Father, has made him known.”
If we read the phrase as “Come, Lord!” it expresses the longing of believers’ hearts that Jesus would return a second time, not as a helpless baby entering into our pain but as a victorious king who comes to set all things right and make all things new. This phrasing reminds us of what the angels told the disciples in Acts 1:
“They were looking intently up into the sky as he was going, when suddenly two men dressed in white stood beside them. ‘Men of Galilee,’ they said, ‘why do you stand here looking into the sky? This same Jesus, who has been taken from you into heaven, will come back in the same way you have seen him go into heaven.’”
More here:
https://www.christianity.com/wiki/christian-terms/what-does-maranatha-mean-in-the-bible.html