As per orthodoxy, there are two kinds of marriage: natural marriage and sacramental marriage. Sacramental marriages exist only between baptized people, so marriages between two non-Catholics/Orthodox is not a sacramental marriage (I'm not sure if you believe in Sacraments or not, but to us a marriage is a sacrament, a divine union between GOD, woman and man -- God is in this, hence we do not believe in divorce.
now, if two non-Catholics get married as per their own or the country's laws, they are natural marriages
Now in the case of Newt's earlier marriages I understand that these were annulled after he petitioned that the prior marriages were not sacraments in the couple's eyes. Without this, he would be considered divorced and hence ineligible for a Church wedding (he could have gotten a civil marriage) -- as I understand the annulment was based on the fact that Marianne was reportedly previously married.
To sum up -- since they were judged annulled, the prior marriages do not count, but the children still "do" in the eyes of the Church.
If a Catholic gets a divorce but no annulment it is a civil ceremony (divorce is civl, annulment is religious), they cannot get married in Church -- can they receive communion? If they have not remarried of course they can receive communion as they would not be in a state of mortal sin (note that all are ABLE to receive communion -- but we believe that if one receives communion when in a state of mortal sin, it is a grave sin against God.) -- the "divorce" does not put one into mortal sin per se. Remarriage after divorce does.
so, if divorced and living celibately, then he may recieve. If he wants to marry again, then an annulment is necessary.
The Catholic Church recognizes any Christian marriage, conducted in a Christian church, to be a sacramental marriage. Thus, an annulment would be required.
Thank you. Totally understand. He skips.