St. Augustine remarked famously in a dictum: "In essentials, unity; in nonessentials, liberty; in all things, charity. Holy Communion or the Eucharist (which means "thanksgiving"), aka the Lord's Supper, first-served in the Upper Room was instituted for the Church as a command to do in remembrance of Jesus and to perpetuate the memory of His death, and the New Covenant by virtue of His shed blood on our behalf. There are no many things all Christians agree on, but this should be a source of unity everywhere, uniting us all. We are showing solidarity in Christ and He has promised a special blessing on it, with a peculiar presence of His divine nature (His human nature is seated at the right hand of the Father in the third heaven).
It is true that "wherever two or three are gathered together in His name that Christ is present in His divine nature ("For lo, I am with you always, even unto the end of the age"). However, there is a special grace of his meeting with us at this ordinance (let's not call it sacrament), which does not convey grace ex opere operato (by virtue of the act per se), but the actual instrumental means of grace is faith, not the outward motions or activities per se.
Some believers go to the extreme of this God-ordained ritual and do it on a daily basis, thinking they are more holy or sanctified that way. We are to "tarry for one another" and therefore this is a group effort to bring the testimony of Christ. This is our chance to regularly "examine" ourselves and that way not partake "unworthily" which could result in divine discipline or death. The table is to be open to all believers who profess saving faith in the Lord Jesus Christ and not discriminating or in any way showing favoritism. We are all equal before the Lord and there are no titles or ranks, classes, or castes. It is the quality, not the quantity of our obedience that the Lord is looking for.
The Lord's Supper is meant to be a meaningful ritual and not an empty one when one just goes through the motions thinking you don't need faith to benefit. It should always be an opportunity to instruct on the Seder that was celebrated by our Lord. It is a celebration and a privilege not to be taken for granted. If we partake and don't discern the body of Christ or have unrepentant sin in our life we bring judgment on ourselves, but only that we don't perish with the world. Soli Deo Gloria!