Hello.
Yes, Peter was married. So were most of the apostles and disciples. What you are forgetting is that Jesus called them when they were already married, and that He called them to:
Luke 14:25-27
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Many people were traveling with Jesus. Jesus said to the people, “If a person comes to me, but will not leave his father, mother, wife, children, brothers, or sisters, then that person cannot be my follower. A person must love me more than he loves anything–even his own life! If a person will not carry the cross (suffering) that is given to him when he follows me, then that person cannot be my follower.” (ERV)*
Peter, himself, also said: “Then answered Peter and said unto him, Behold, we have forsaken all, and followed thee; what shall we have therefore?” (Matthew 19:27, KJV)
Jesus, time and time again, told the apostles that in order to follow him, they must leave behind everything. The apostles did just that; they left their families, homes, jobs, etc. Almost all of them did other things before they knew Jesus and were His follower exclusively: they were fishermen, tax collectors, physicians, scribes, etc. Most were also fathers and husbands. But Jesus was adamant that in order to be His follower, they had to leave everything and follow Him, and be ready to do that at a moment’s notice.
Of course, Biblical scholars and different denominations of Christianity interpret that differently, which is why some denominations’ clergy are allowed to marry and others are not. Catholic priests, nuns, and consecrated individuals are making the choice to be “married to the Church” and to live their lives completely immersed in Christ and His Church, with no distractions. Anyone who is married or is a parent knows that their spouse or their child rightly will take up a good deal of their time or attention. There is nothing wrong with the married vocation in life. The Catholic Church sees it as a Sacrament, in fact! We just view Vocations/Holy Orders and Marriage as two separate ways of life that really can’t be mixed; it would rather be like trying to serve two masters. How could someone, really, give their life 100% to the Church when they are trying to raise a family and/or support a spouse mentally, emotionally, physically, etc? Our religious also take a vow of celibacy, that they give this great gift of sexuality to God. It doesn’t mean that married people are “lesser than”, just different.
For those in the Catholic Church who feel a call to serve the Church in a more dedicated way than a layperson, but who wish to remain or to be married, there is the service of being a Deacon. Deacons can be married and serve a very important place in the Church.
I hope this answered your question, at least to some degree.
God Bless.