Christianity is a religion established by Jesus Christ and all followers of Christ and his teachings in accordance with the Bible— called Christian, be it Catholic, Protestant, Orthodox, Anglican, Gnostic, Mormon, Evangelical, among other sub-branches of Christianity.
Meanwhile, a Catholic is a Christian who believes in fundamental Christian values but as transmitted by the succession of Popes. Catholic believes in the special authority of the Pope, which other divisions of Christianity may not believe in.
While, Jesus Christ is the founder of Christianity in general, the credit of establishing Catholicism goes to St. Peter the Apostle, when Christ chose St. Peter as the first Pope (His Rock).
Differences
To interpret the difference between a Catholic and a Christian, one has to essentially understand that a Christian is someone who follows the religion of Christianity with all its subdivisions, while Catholic is someone who follows the Catholicism sect of Christianity. In other words, all Catholics are Christians, but all Christians are not Catholics.
It is to be understood that for around a thousand years Catholicism and Christianity were the same things. The split with the Orthodox Christians in 1054 A.D. gave rise to the schism between the Church of Rome and other Christian faiths.
The Catholic Church is the largest Christian ecclesiastical body in the world, with over a billion members worldwide.
The difference between Catholics and Christian arose in terms of doctrines, absolute authorities, and behavior of the popes. The establishment of the Protestant churches in the sixteenth century further subdivided Christianity.
Beliefs
The Catholics believe the Roman Catholic Church to be their supreme authority, while Christians, in general, have their belief set on all churches as well as other sources that may exclude churches.
There are many modern practitioners who believe in Christ, are not active churchgoers. The Christians may worship in the chapel, the cathedral, basilica, personal dwellings, or even home bible studies.
Structure of St. Augustine Roman Catholic Church, vs. Episcopal church in Detroit, Michigan, Christ Church Detroit
The belief of Catholics is centered in Jesus Christ as the Messiah, the King of Heaven, and the savior of the whole world. The Christians, on the other hand, believe in the Holy Trinity, which is a summary of Christian belief by the Nicene Creed.
The life after death is about Eternal Salvation in Heaven, Purgatory (the third temporal stage before heaven), or about eternal damnation in hell for the catholic. The Christian belief is centered on eternality in heaven, hell, or temporal purgatory.
The difference between the two groups concerns The Virgin Mary, Mother of the Son of God. The Virgin Mary is considered as the Queen of Saints by the Catholics and is considered as the leader and the highest saint of all saints. For the Christians, The Virgin Mary's body was buried when she died. The Catholics consider her to be without any sin, and her resurrected body ascended to heaven immediately. The Christians believe that The Virgin Mary was full of sin, just like every other human.
Regarding homosexuality, the majority of Christians throughout history have viewed it as immoral and sinful. But this system of thought has taken a turn as in the past century, many prominent Christian religious groups and theologians have adopted a wide variety of beliefs and practices, with some congregations being considered 'open and acceptable.'
In Catholicism, though, the acts of homosexuality are considered to be contrary to the laws of nature and also sinful. Homosexual desires are also considered to be disordered. But, the fact remains that both the Christian denominations and the Catholic Church have had priests and pastors who were gay although, homosexual priests have been reprimanded by the Catholic Church.
The Holy Bible
The Holy Bible, which is the collection of a total of 73 canonical books consisting of two parts: 46 in the Old Testament and 27 in the New Testament, is the common scripture that both Catholics and the majority of the Christians consider to be of utmost importance. The Bible, therefore, is an important part of every Mass. The entire Mass has the Bible woven throughout.
Regarding the Mass, Catholics can attend them multiple times during the day and throughout the week, while most Christians attend mass on Sundays only apart from religious days of prayer, New Years Day Eve, or New Years Day. Catholics' place of worship is confined to the churches, chapels, cathedrals or basilicas. The Christians can worship at any dwellings.
The Pope
For the Catholics, the Pope is Gods' representative on earth who has the authority over the interpretation of the scripture, The Holy Bible. For them, the Pope instills are law themselves, which should be adhered to as the word of God himself even if it contradicts the laws of the land. This interpretation has resulted in many Catholics being at odds with other Christians.
On the other hand, for the Christians in general, the Pope is only someone who is the head of the Church. They do not acknowledge the authority of the Pope to the extent of the Catholics. Hence, they do not believe in the Pope's supremacy or infallibility. For them, the Holy Bible is the word of God, according to Jesus. Additionally, Christians do not necessarily follow the religious leaders or their teachings and believe that church leaders can provide advice and guidance at most.
Can Catholic And Christian Stay In Relationship?
Christians believe marriage to be a gift from God, which is a public declaration of commitment and love. It provides the appropriate environment to engage in sexual relations and then build a family life. But marriage should be conducted in a church, in the presence of God, and that is considered to be very important.
The Catholics consider marriage (civil marriage) in the Catholic Church to be a sacrament in participation in God's free, faithful, total, and life-giving love for the spouse, humanity, and the Church. The couples wanting to marry in the Catholic Church have to approach their parish priest, who advises them on a program of marriage preparation and discernment. Couples are usually asked to provide six months prior notice to the deacon or the officiating priest.
Marriage Between Catholic And Christian
While Catholic marrying outside of the faith was pretty rare, things have started to change recently. Many people now are open to dating life and marriage across religious faiths. For a Catholic who is a baptized Christian, the marriage is considered to be valid if the Catholic party obtains permission from the diocese and follows all practices of a Catholic wedding.
Marriage between a Christian and Catholic is also considered to be a sacrament. The matter of fact remains that the Church regards all marriages between Christians as sacramental as long as the Christians are baptized.
In cases of Catholic marrying a non-baptized Christian, which is also known as a marriage with disparity of cult, the church exercises a more rigorous form of permission from the local bishop for the marriage to be valid where the church exercises more caution. The union of a Catholic and a non-baptized Christian is not considered sacramental.
Wedding Ceremony
Since marriage is a very sacred event for the Catholics, the Church prefers the marriage to be held in a Catholic Church, preferably the parish church of the Catholic party. In order to marry elsewhere, the local bishop should provide special permission, which includes providing a good reason. This type of permission is known as "dispensation from canonical form" without which the wedding in the Catholic Church is not considered to be valid.
It is recommended for such interfaith weddings not to include Communion, which results in most interfaith weddings to take place outside of the Mass. If an ecumenical couple wishes to wed within the mass, they must attain permission from the bishop.
Representations
The Catholics accept the depiction of Jesus Christ, the Virgin Mary, or any other Saints in the form of statues or pictures. The Christians, in general, limit such depictions to the churches, chapels, or cathedrals.
The Catholics can display the depictions in the walls at homes, as jewelry or as tattoos in the body, while some variations of the Christian faith forbid the depiction of Christ, allowing space for using a simple wooden cross as expression.
Similarities
Both Catholics and Christians believe in the existence of the only one God and in that Jesus is God the son in the form of human flesh. Other similarities between the two groups include the agreement that God is rightly angry with humans, for they have not treated him or other people like they should have. They also agree that God will bring everyone to life after death and judge them based on the way they have lived their life.
The similarities in their belief are that both belief in the virgin birth of Jesus through God, in that God is the father of all mankind and also that there is the second coming of Christ as the promised holy one. Additionally, belief in the Ten Commandments as moral compasses; in baptism as a rite of becoming a Christian, which removes the original sin that all mankind is born too are the characteristic of the Catholic.
Both Catholics and Christians also believe that Jesus came to the earth to help out humans with their problems, and he died on the cross as a punishment for humans.