3Ne Ch18

Just like before He died, Christ institutes the sacrament to His people and teaches the principles of praying in His name and taking it worthily. Then He gives his disciples the power to confer the Holy Ghost upon those who are righteous and worthy.
Everyone is gathered to sit while the disciples bring bread and wine to watch Christ as He blesses the bread and gives it to His disciples, who are then the ones to pass it to each of the multitude present (v1-4). Christ explains that there will be someone who will be ordained to perform the ordinance of the sacrament in remembrance of His body and blood as a testimony unto the Father they whomever partakes of it remembers Christ and shall have His spirit to be with them (v5-7). He then blesses the wine which is distributed as the bread was to everyone, and Christ says that all who have partaken have done this as a witness that they are willing to follow His commandments in remembrance of the blood that was shed for them by Christ (v8-11).
Christ goes on to say to the disciples and then the people, that they will be blessed with a strong foundation if they keep the commandments, constantly watching and praying so they are not taken captive by the devil (v12-19).  It is important to pray in all places for all that is asked shall be given, and meet together without casting anyone out but praying for any who do not meet with you to join and receive the light of Christ in their lives like you have (v20-25). To His disciples, Jesus warns of the evil of partaking the sacrament unworthily, and tells them to forbid anyone who would try because it would be like drinking damnation, but never cast them out of sinning because they need more prayer and help to repent than others (v26-30).
Those who do not repent of their sins will not be numbered as Christ's sheep, but it is not our job to decide who is allowed to come to church, so we are commanded to always welcome all into our houses of worship and be open hearted (v31-33). The Nephites have been known for their disputations, so Christ commands that they stop and they will be blessed as His last words before returning to report to His Father (v34-35). He actually said more to each disciple as He touched them and spoke words that only the disciples heard and said they He gave them the power to give the Holy Ghost (v36-37). Jesus left after blessing each of the twelve, but he was mysterious enough to have a cloud overshadow the multitude so that he could ascend again to heaven (v38-39).