What is the Church's stand concerning marriage and divorce?
Key Verse:  And said, For this cause shall a man leave father and mother, and shall cleave to his wife: and they twain shall be one flesh?  Wherefore they are no more twain, but one flesh. What therefore God hath joined together, let not man put asunder.  [Matthew 19:5-6]
Marriage

When man and woman are joined together they become one flesh as the scriptures verify, living for each other and seeking God's will for instruction.  No man has the authority to separate them, for marriage is of God.

And said, For this cause shall a man leave father and mother, and shall cleave to his wife: and they twain shall be one flesh?  Wherefore they are no more twain, but one flesh. What therefore God hath joined together, let not man put asunder.  [Matthew 19:5-6]

So ought men to love their wives as their own bodies. He that loveth his wife loveth himself.  [Ephesians 5:28]

Husbands and wives ought to love each other in the Lord, to love each other is to walk in the harmony of the word of God.  God doesn't just want to be our marriage councellor, he wants us to have a relationship with him.

This is a great mystery: but I speak concerning Christ and the church.  [Ephesians 5:32]

The Lord compares matrimony as his Holy Spirit and the children of God walking in accordance with God's divine instruction, oneness.

Divorce and Remarriage

And the Pharisees came to him, and asked him, Is it lawful for a man to put away his wife? tempting him.  And he answered and said unto them, What did Moses command you?  And they said, Moses suffered to write a bill of divorcement, and to put her away.  And Jesus answered and said unto them, For the hardness of your heart he wrote you this precept.  [Mark10:2-5]

We can see here that Jesus did not support the idea of man putting his wife away but enforced His Father's word that no man would separate what He had joined. 

While one is truly married, can he or she be joined to another without committing adultery?

Whosoever putteth away his wife, and marrieth another, committeth adultery: and whosoever marrieth her that is put away from her husband committeth adultery.  [Luke 16:18]

Do the scriptures show exceptions to the above rule? 

The wife is bound by the law as long as her husband liveth; but if her husband be dead, she is at liberty to be married to whom she will; only in the Lord.  [1 Corinthians 7:39]

And I say unto you, Whosoever shall put away his wife, except it be for fornication, and shall marry another, committeth adultery: and whoso marrieth her which is put away doth commit adultery.  [Matthew 19:9]

What instructions do we get concerning those who are truly married, or who God hath truly joined together?

And unto the married I command, yet not I, but the Lord, Let not the wife depart from her husband:  But and if she depart, let her remain unmarried, or be reconciled to her husband: and let not the husband put away his wife.  [1 Corinthians 7:10-11]

Note: The Church of God stands opposed to divorce and remarriage for any cause except as recorded in Matthew 19:9.