In his dream, Lehi looked around and saw his family. What were they doing? They were searching. Lehi observed that it looked like they were lost. As a good father, what did Lehi instinctively do? He beckoned them by calling out with a loud voice. Notice that Lehi did not go and get them. Even though they were confused and lost, he still required them to come to him and the tree. He beckoned; he did not force them to come. Sariah, Sam, and Nephi chose to follow the path and partake of the tree. He could not make Laman and Lemuel come to the tree, and they chose not to do so. But Lehi was there. He invited, and he did it with a loud, clear voice so they would not miss it.
If you or someone you love is lost, it is not the end of the story. Even those who have wandered off will be brought to the tree or given opportunities in the next life. The Lord continues to work with people as they exercise their agency, and He continues to beckon and do all He possibly can to try to lead them back on the righteous path of happiness. Brigham Young once said, "How long will this missionary work go on?" His answer was, "It will go on in the next life and it will continue and it will go on and on until every soul that possibly can be saved has been saved, and we are not going to be finished until we have reached that point."
Noel B. Reynolds, "How ‘Come unto Me’ Fits into the Nephite Gospel," Religious Educator 18, no. 2 (2017): 14–29.
"Returning to the metaphor of the gospel as the path or the way that leads to eternal life, with repentance and baptism providing the gate into that path, the invitation to come unto me appears to be addressed to those who have entered the path already as encouragement to stay on it or return to it—to follow the Spirit that leads them back to the Lord, day by day, sanctifying them in the process." (p. 28)