From your final statement I infer that you do not see the need for confession and that you advocate open communion. Do I understand you correctly?
In medieval times, it was believed that if you did not have a chance to confess before you died (got “shriven” of your sins), that you would go to hell. It is true that from the beginning of Christianity, God has given priests the power to forgive sins. He does this in John 20:21, where Jesus tells his disciples, “those whose sins you forgive are forgiven them; those whose sins you retain are retained.” However, the Church points out that even if a priest forgives your sins, if you are not truly repentant then God does not forgive your sin, because God sees into your heart. But the converse of this statement must then by extension be true — that even if a priest does not forgive your sins (e.g. b/c you have not had a chance to go to confession), if you are truly repentant then God will forgive your sins, because God sees into your heart. What makes Confession to a priest truly important is its difficulty. Too often people ask God to forgive them in private prayer, but because God does not (usually answer) and they cannot (usually) see God, it is easy to believe that they have truly repented and are thus forgiven. Confessing to a priest forces a person to fully confront the shame of their sin, helping them reach true repentance. If, however, say they were to die before they had a chance to confess, if they have reached a state of true repentance and accept the gift of God’s grace in their hearts, then do you believe that Jesus would not forgive them? Even the popes and the Council of Trent agree that He would. To quote, they say “it sometimes happens that this contrition is perfect and that it reconciles man with God before the actual reception of this sacrament, still the reconciliation is not to be ascribed to the contrition itself apart from the desire of the sacrament which it (contrition) includes.” What this means that if a person is truly repentant and desire to confesses (i.e., he would confess if a confessor were accessible, and he realizes that he is obliged to confess when he has the opportunity), then God will forgive them whether or not they ever have the opportunity to go to confession.
I do not think you can consider what I “advocate” as open communion, since most other Christian denominations, and certainly all non-Christians, do not believe that the Eucharist is really the Body and Blood of Christ. They see it as symbolic only, in which case to eat and drink it would to them be literally only eating and drinking, which as Paul says is taking the Eucharist in an unworthy manner. Again, Paul’s point was not that sin made a person unworthy of communion, but gorging on and treating God’s Body as nothing more than bread was disrespectful and unworthy.
However, Jesus says that if I person does not eat of his body and drink of his blood, then they do not have life within them (John 6:53-58). If a person has come to believe and accept the True Eucharist with all their heart, and desires it, what right have we to keep it from them? If they were to die before the church deems them “ready” to have first communion (a process that could take a year or longer in some places), then technically we have condemned their souls to eternal death. And that’s just the case for non-Catholics.
Consider the case of the Catholic person who started this thread. I know their question was hypothetical, but for the sake of argument, let’s say they are in a state of mortal sin and truly repent of it. Also for sake of argument, let’s say that they could not attend confession until after the next communion. Here is a person who believes that the bread and wine is the Blood and Body of Christ, and who truly repents of their sin. According to the Council of Trent, God has already reconciled them, even before they have gone to confessions. Should they then still be denied Jesus? One might say that they can wait to have communion until after they are officially shriven, but what if they were to die before then? Would they then go to hell because they did not have a chance to officially confess their sins? If you believe, as I do, that Jesus would not condemn them in death because they have repented and desire his forgiveness, then why would He deny them the forgiveness of his Communion in life?