Mary, Jesus' mother remained a virgin for her entire life. Is this doctrine according to the Bible?

Does the Holy Bible teach about the perpetual virginity of Mary?"

The Roman Catholic Church believes that Mary, Jesus' mother remained a virgin for her entire life. Is this doctrine according to the Bible?

"Mother of God" and "Queen of Heaven" are two of the many titles that the Roman Catholic Church has ascribed to Mary. 

Catholics believe that Mary has an exalted place in Heaven, with the closest access to Jesus and God the Father. Nowhere in Scripture is this idea found.

Even if Mary does occupy such a glorified position, her having sexual intercourse with her husband Joseph would not have prevented her from gaining such a position.

Sex in marriage is not sinful. Mary would have not defiled herself by having sexual relations with Joseph. The entire concept of the perpetual virginity of Mary is based on an unbiblical teaching, Mary as Queen of Heaven, and on an unbiblical understanding of sex.

So, what does the Bible say about the perpetual virginity of Mary?

The New American Bible, which is a Catholic translation of the Bible, does not teach the perpetual virginity of Mary. 

We read that "He (Joseph) had no relations with her until she bore a son, and he named him Jesus" (Matthew 1:25 NAB).

Joseph did not have any sexual relations with her (Mary) UNTIL after she bore a son - Jesus. Let us state it in another way: Mary did not have sexual relations

with her husband Joseph “until she bore a son, and he named him Jesus"

This Scripture is clearly illustrates that Joseph and Mary did not have sexual relations until after Jesus was born. 

In Matthew 13:55-56 NAB Jesus was identified as the son of Joseph the carpenter "Is He not the carpenter's

son? Is not his mother named Mary and his brothers James, Joseph, Simon, and Judas? Are not His sisters all with us?"

Catholics interpret that the Greek term for "brothers" (υἱός uihos hwee-os') and "sisters" (ἀδελφή adelphē ad-el-fay') could also refer to male and female relatives, not necessarily literal brothers and sisters.

However, the intended meaning is clear. They thought Jesus to be Joseph's son and the son of Mary, and the brother of James, Joseph, Simon, and Judas, and the brother of the unnamed and unnumbered sisters. The relationship thus goes from father, to mother, to brothers and sisters.

The text, in no way could “brothers” and “sisters” be interpreted as "cousins" or "relatives" with the mentioning of Jesus' mother and father.

Further, we read in Matthew 12:46 NAB,"While He was still speaking to the crowds, His mother and His brothers appeared outside, wishing to speak with Him."

See also: Mark 3:31-34 Jesus' Mother and Brothers

“31 And his mother and his brothers came, and standing outside they sent to him and called him. 32 And a crowd was sitting around him, and they said to him, ‘Your mother and your brothers are outside, seeking you.’      33 And he answered them, ‘Who are my mother and my brothers?’              34 And looking about at those who sat around him, he said, ‘Here are my mother and my brothers! ‘” (ESV)

Luke 8:19-21       Jesus' Mother and Brothers

“19 Then his mother and his brothers came to him, but they could not reach him because of the crowd. 20 And he was told, ‘Your mother and your brothers are standing outside, desiring to see you.’ 21 But he answered them, ‘My mother and my brothers are those who hear the word of God and do it.’” (ESV)

John 2:12 “After this he went down to Capernaum, with his mother and his brothers and his disciples, and they stayed there for a few days.” (ESV)

Acts 1:14 “All these with one accord were devoting themselves to prayer, together with the women and Mary the mother of Jesus, and his brothers.” (ESV)

All above texts mention Jesus' mother with His brothers. If they were His cousins, or the sons of Joseph from a previous marriage, why were they

mentioned with Mary so often?

The idea of the perpetual virginity of Mary cannot be proven in Scriptures. It must be forced on Scriptures, in contradiction to what Scriptures clearly state.

If such doctrine is not found in the Bible what is the assurance of the believers that what they have been taught and believed in is the truth?

The Lord Jesus Christ warned about this:

“in vain do they worship me, teaching as doctrines the commandments of men.” (Matthew 15:9) (ESV)

“in vain do they worship me, teaching as doctrines the commandments of men.” (Mark 7:7) (ESV)

Even the apostle Paul wrote about this:

^“so that we may no longer be children, tossed to and fro by the waves and carried about by every wind of doctrine, by human cunning, by craftiness in deceitful schemes.” (Ephesians 4:14) (ESV)