This Supper is all about the future. This is an eschatological meal at the end of the world that we are privileged to share in now. Just as the Spirit of God escorts us all into the heavenly places so that we may partake of the living Christ there, so also the Spirit unites past, present and future in such a way as to enable every true Christian to partake of eternal life now.
The one who believes in Jesus has eternal life, and has eternal life as a present possession. “Whoso eateth my flesh, and drinketh my blood, hath eternal life; and I will raise him up at the last day” (John 6:54).
There is a mystery here because false Christians can certainly partake of the Supper in some fashion, which is why Paul says that their unbelief makes them guilty of the body and blood of (1 Cor. 11:27). You can’t defile something you have no connection with. Just as they have some sort of union with Christ (John 15:1-6), so also they have some way of trampling the blood of the covenant by which they were sanctified (Heb. 10:29). There is a connection there, but it is not a life-giving connection.
But just as there are Christians and then real Christians, so also there is partaking and real partaking. Real partaking is by faith alone, and real partaking is efficacious. Going back to John 6:54, if someone eats Christ’s body and drinks His blood, what may we then say is the case? We may say that he has, right now, eternal life, and we may say that God has promised to raise him up at the last day.
Someone who is not so raised is therefore someone who never had the promise that he would be raised. God breaks all kinds of things—worlds and kingdoms, heads and hearts, princes and presidents, and constellations in the heavens. God breaks the pride of man, but He never breaks a promise. This means that someone who is not so raised is someone who never had that eternal life.
But we are convinced of much better things in your case. This meal is offered to you here as an earnest on your final inheritance. If you receive it in true evangelical faith, with a humble heart, and without blowing any smoke at God, then you may marvel at what you are being given. This bread and this wine are eternal life. They are being given to you. They are yours. You may put them in your mouth.
So come, and welcome, to Jesus Christ.