The Gospel passage and the first reading of this Sunday indicate that the theme of our reflection should be marriage and the family.
A subject of utmost importance to which these few lines will do no justice.
I will make a simple statement of the points of Catholic doctrine on the subject.
In the first place, marriage is a reality that belongs to the realm of creation and is founded on human nature created as man and woman in view of reproduction and mutual help.
It is not good for man to be alone, God thinks and decides to create companionship for the male.
God first creates the animals. 
They coexist with the man, but they do not keep him company nor are they his sexual counterpart.
They are not his equal.
And God’s observation still serves as a warning to those who want to make animals companions so as not to have to do with human beings.
Dogs and cats and other pets are no substitute for children and friends.
God creates the woman from the rib of the man to indicate their equality of rank and dignity and sexual complementarity.
In the dimension of affection and sexuality, man is made for woman and woman for man.
Other arrangements are not consistent with the structure of creation.
Christ elevated this natural reality to the rank of a sacrament and placed human love in the dynamic of his own love for the Church.
For this reason, marriage in Catholicism has three characteristics.
First, it is exclusive.
That is, it is the union of a single man with a single woman to the exclusion of any other type of relationship that reaches conjugal affection and sexual intimacy with a third or fourth person.
The spouses must remain faithful to each other.
This is a requirement explicitly protected by the sixth commandment: you shall not commit adultery.
Secondly, marriage in Catholicism is indissoluble until the death of one of the spouses.
This characteristic implies that this union is so profound that it is not to be trifled with or entered into lightly; spouses must take each other seriously.
This characteristic demands that couples reflect before committing themselves to the union and mature in their project in the face of adversities and disagreements. 
The thoughtless and frivolous marriage can even be null and void.
The perpetuity of the union demands personal maturity from the spouses.
It is a call to grow and mature as a couple.
The third characteristic of Catholic marriage is fruitfulness.
The explicit and practical exclusion of children from the beginning of the union renders the marriage null and void.
In fact, marriage is not validated as long as the couple does not have intimate relations in the human way and open to life.
This is how important this dimension of fertility is.
Another thing is when for biological reasons the couple cannot have children and both accept that reality.
But the purpose of marriage is the generation and education of children. 
Without them, it is incomplete.
Marriage is the foundation of the family.
And the family is the foundation of society and the place where individuals and lay believers are projected into society to fulfill their mission and vocation.
Marriage in Catholicism presupposes faith in Christ in order to live it up to his demands.
Brides and grooms without faith in God, who marry in church for merely aesthetic reasons, also marry in vain.
May the Lord grant that all Catholic couples who begin their marriage project take into account from the beginning these characteristics of the marriage they are contracting, strengthen their faith and attain holiness and salvation.