Actually the former is more Biblical by examples:
"Sirs, what must I do to be saved?" They replied, "Believe in the Lord Jesus, and you will be saved" Acts 16:30,31
"If you confess with your mouth, "Jesus is Lord," and believe in your heart that God raised him from the dead, you will be saved. For it is with your heart that you believe and are justified, and it is with your mouth that you confess and are saved. As the Scripture says, "Anyone who trusts in him will never be put to shame." For there is no difference between Jew and Gentile— the same Lord is Lord of all and richly blesses all who call on him, for, "Everyone who calls on the name of the Lord will be saved." Rom 10:9-13
Interesting in that passage because "Lord" is being reference relative to an Old Testament passage which is talking about the Lord God. He's not simply the Messiah, He's the Lord God. This speaks not only of the deity of Christ being something one must believe to be saved, but also acknowledging Jesus as "Lord" means the person is pledging allegiance to do what he says, as Jesus said, "Why do you call me, ‘Lord, Lord,’ and do not do what I say?" Lk 6:46
How about the gospel preached to Cornelius?
Acts 10:36-43
You know the message God sent to the people of Israel, telling the good news of peace through Jesus Christ, who is Lord of all. You know what has happened throughout Judea, beginning in Galilee after the baptism that John preached— how God anointed Jesus of Nazareth with the Holy Spirit and power, and how he went around doing good and healing all who were under the power of the devil, because God was with him. We are witnesses of everything he did in the country of the Jews and in Jerusalem. They killed him by hanging him on a tree, but God raised him from the dead on the third day and caused him to be seen. He was not seen by all the people, but by witnesses whom God had already chosen— by us who ate and drank with him after he rose from the dead. He commanded us to preach to the people and to testify that he is the one whom God appointed as judge of the living and the dead.All the prophets testify about him that everyone who believes in him receives forgiveness of sins through his name."
So again, Jesus is Lord is typically mention in gospel presentations in the Bible, as well as his resurrection from the dead.