Tom Hoopes at Catholic Vote has written a piece entitled Popes Clearly Say Who Can and Can't Receive Communion.
He concludes his article ...
In their 2006 document, “Happy Are Those Who Are Called to His Supper: On Preparing to Receive Christ Worthily in the Eucharist,” the bishops pointed out that communion is not just for Catholics only, but only for Catholics who:— Went to confession in the past year, at least, or after they committed a serious sin.— Fasted for an hour first “refraining from food and drink (except for water and medicines) for at least one hour prior to receiving Holy Communion.”— Are wearing “modest and tasteful dress” — “clothes that reflect our reverence for God and that manifest our respect for the dignity of the liturgy and for one another.”— Are in a recollected and prayerful state of mind.The statement even spells out some common serious sins. These are sins that constitute grave matter. When we do them deliberately and with knowledge of their sinfulness, they put us in a state of mortal sin.• Abortion and euthanasia. “Committing murder, including abortion and euthanasia, harboring deliberate hatred of others.”• Any extra-marital sex. “Engaging in sexual activity outside the bonds of a valid marriage.”• Theft, including “serious fraud, or other immoral business practices.”• Slander, Hatred and Envy. “Speaking maliciously or slandering people in a way that seriously undermines their good name. … Harboring deliberate hatred of others. … Engaging in envy that leads one to wish grave harm to someone else.”• Pornography. “Producing, marketing, or indulging in pornography.”
***So don’t think the Church is being mean for denying communion to politicians who reject the right to life for the unborn. Communion with Our Lord is a precious privilege, not a common right. Every one of us should be more careful about approaching it worthily.
I must admit that I'm not always dressed appropriately to attend Mass, much less receive communion. Sometimes this is because I'm walking to church, and (especially in the summer heat) I can't walk for several miles in church clothes.
But I often find myself not in a "recollected and prayerful state of mind". This is usually because I'm on the road and I'm fulfilling my obligation at a random church - and at least half the time the priest is playing games with the liturgy, and the music is so dreadfully contrary to recollection and prayer that I find Mass more of a temptation to Wrath than a spiritually nourishing activity. I have occasionally decided not to receive because the entire celebration was so antithetical to anything Catholic or even Christian that I could not lie with my body and tell everyone around me (by receiving) that we were all in communion together, when they really didn't seem to belong to the same Church I do.
Anyway, it's good to know the Church still takes reception seriously - although your parish priest or your bishop would probably never give a hint that any of this still matters.