I offer the following thoughts on closed communion.
First, when someone refers to closed communion, one should always first find out what they mean by that term. The term is not one of those terms with widespread theological acceptance. However, generally, closed communion is the practice of restricting the serving of the elements to those who are members of a particular church, denomination, or sect. That is, those churches practicing closed communion limit participation in the elements either to members of their own church, or members of their own denomination or group. They do not allow other believers who are not members of their church or denomination to participate in the elements. In contrast, those who practice open communion allow all adult believers in and followers of Jesus, who are not living in known sin, to join in the elements of communion, even if they are members of another church, group, or denomination.
There is no direct Scriptural support for closed communion. Communion arose out of the Last Supper which was a passover dinner. Interestingly, all of the disciples were allowed, yes even commanded, to participate. Paul, in 1 Corinthians, chastises the believers for not openly sharing their meal with the poor in chapter 11, verses 17-22, then he launches into his instruction on the Lord’s Supper. There is no indication that it was limited to members of a particular church. I note that in Matthew 26:29, Jesus links the Lord’s Supper to the feast in heaven when He promises to drink with the believers. There, certainly, all believers will be gathered in one place. They will not be divided by denomination, group, or local church.
Those who believe in closed communion do so on the basis of their ecclesiology (doctrine of the church), not on direct Scriptural support. Some believe that they are the only true church and therefore Christians not a part of their church are not following God. For this reason, they should not partake of communion. Others believe that God ordained local churches and the concept of a universal church is not in their belief system. They also prohibit others from partaking in communion. There may be other reasons for some following a closed communion, but I am not aware of them.