There are religions whose doctrine believe that Mary did not had other children except Jesus only. The Bible verses that we can read and give proof to Jesus’ brothers were interpreted by them as those were only cousins, or kins or from a suppose earlier marriage of Joseph, the husband of Mary.
What are these verses?  Matthew 13:55-56 & Mark 6:3

Mat 13:55 Is not this the carpenter’s son? Is not his mother called Mary? And his brothers, James and Joses and Simon and Judas,

Mat 13:56 and his sisters, are they not all with us? Then from where does this man have all these things?

Mar 6:3 Is not this the carpenter, the son of Mary, the brother of James and Joses and Judas and Simon? And are not his sisters here with us? And they were offended at Him.

The Greek word used for the term brother is ἀδελφός (adelphos), which is a connective particle and δελφύς delphus (the womb); a brother (literally or figuratively) near or remote (much like [H1]): – brother. Sister, meanwhile is ἀδελφή (adelphē), the feminine of adelphos, which means a sister.

From the original, we can learn that it cannot be meant as “Cousins” simply because in Colossians 4: 10, the original word for cousin is ἀνέψιος (anepsios), (as a particle of union) and an obsolete form νέπος nepos (a brood); properly akin, that is, (specifically) a cousin: – sister’s son.

Col 4:10 Aristarchus my fellow prisoner greets you, and Mark, the cousin of Barnabas (regarding whom you received commandments; if he comes to you, receive him),

This is what the other religion/s say about this verses:  ”The Church has always understood these passages as not referring to other children of the Virgin Mary. In fact James and Joseph, ‘brothers of Jesus,’ are the sons of another Mary, a disciple of Christ…” Pg. 126 #500).

They interpret these passages that the Mary here is the mother of Jesus, but the brothers and sisters of Jesus mentioned are children not of Mary but of another woman whose also named as Mary. But it’s very clear here without assuming anything, that the children are the offspring of the Mary of this passage and having said that it is different Mary doesn’t give any proof.

Let’s read again from the Bible and check if we can agree with them who say that the Mary of these passages is both the mother of Jesus and the mother of James and Joseph and Simon and Judas.

Matthew 13:55-56 ”Is not this the carpenter’s son? Is not His mother called Mary, and His brothers, James and Joseph and Simon and Judas? 56 “And His sisters, are they not all with us? Where then did this man get all these things?” 57 And they took offense at Him. But Jesus said to them, “A prophet is not without honor except in his home town, and in his own household.”

Mark 6:3 “Is not this the carpenter, the son of Mary, and brother of James, and Joseph, and Judas, and Simon? Are not His sisters here with us?” And they took offense at Him. 4 And Jesus said to them, ”A prophet is not without honor except in his home town and among his own relatives and in his own household.”

In both books, there were clear proofs that Jesus had brothers, and their mother is Mary.

In Matthew 12: 46, we can read, But while He yet talked with the people, behold, His mother and His brothers stood outside, desiring to speak with Him. If we try to look the original version, the word “brother” here was translated as adelphos – meaning brother and not anepsios – meaning cousin.

This is the same with what is written in Mark 3:31 Then His brothers and His mother came. And standing outside, they sent to Him, calling Him and also in Luke 8:19 And His mother and His brothers came to Him. And they could not come near Him because of the crowd. Here, we can see that it was someone else who called them “mothers and brothers” and not Jesus. If the brothers are not literal, then neither is the mother. It can’t be cousins as they claim, because in Colossians 4:10, it uses a separate and different Greek word. If we check and read John 1: 41, it uses the same term of Peter and his brother.

Joh 1:41 He first findeth his own brother Simon, and saith unto him, We have found the Messias, which is, being interpreted, the Christ.

In Matthew 1:23-25, we can clearly read that Joseph was commanded to keep Mary a virgin until she gave a birth to a Son. 24 And Joseph arose from his sleep, and did as the angel of the Lord commanded him, and took her as his wife, 25 and kept her a virgin until she gave birth to a Son; and he called His name Jesus.

The following verses give proof that Jesus had literal blood brothers through Mary. We can notice that the word brother cannot refer to brethren in the church because other brethren in the church are listed beside Jesus brothers. Of the 20+ times “Jesus brothers” are referred to. NEVER are they called cousins or relatives.

John 2:12 & John 7:1 & Acts 1:14 & Galatians 1:19 & 1 Corinthians 9:5

John 2:12 After this He went down to Capernaum, He and His mother, and His brothers, and His disciples; and there they stayed a few days.

John 7:1 And after these things Jesus was walking in Galilee; for He was unwilling to walk in Judea, because the Jews were seeking to kill Him. 2 Now the feast of the Jews, the Feast of Booths, was at hand. 3 His brothers therefore said to Him, “Depart from here, and go into Judea, that Your disciples also may behold Your works which You are doing. 4 “For no one does anything in secret, when he himself seeks to be known publicly. If You do these things, show Yourself to the world.” 5 For not even His brothers were believing in Him. 6 Jesus therefore *said to them, ”My time is not yet at hand, but your time is always opportune. 7 ”The world cannot hate you; but it hates Me because I testify of it, that its deeds are evil. 8 ”Go up to the feast yourselves; I do not go up to this feast because My time has not yet fully come.” 9 And having said these things to them, He stayed in Galilee. 10 But when His brothers had gone up to the feast, then He Himself also went up, not publicly, but as it were, in secret.

Acts 1:14 And when they had entered, they went up to the upper room, where they were staying; that is, Peter and John and James and Andrew, Philip and Thomas, Bartholomew and Matthew, Jamesthe son of Alphaeus, and Simon the Zealot, and Judas the son of James. 14 These all with one mind were continually devoting themselves to prayer, along with the women, and Mary the mother of Jesus, and with His brothers.

Galatians 1:18 Then three years later I went up to Jerusalem to become acquainted with Cephas, and stayed with him fifteen days. 19 But I did not see any other of the apostles except James, the Lord’s brother.

1 Corinthians 9:4 Do we not have a right to eat and drink? 5 Do we not have a right to take along a believing wife, even as the rest of the apostles, and the brothers of the Lord, and Cephas?

Colossians 4:10, Aristarchus, my fellow prisoner, sends you his greetings; and also Barnabas’ cousin Mark (about whom you received instructions: if he comes to you, welcome him); Here, it is very clear that it cannot be cousins because it uses different Greek word.

In John 1:41, the term brother is never used in the New Testament to denote a cousin or relative or anything other than a literal BROTHER. John 1:41 He *found first his own brother Simon, and *said to him, “We have found the Messiah.”

Which do we trust now, the original version of the scripture or the baseless assumptions of other religions?