Why did Ezra weep? That is, what specific sin caused him to grieve in such a dramatic fashion?
The answer is this: the people of God had taken the daughters of the surrounding cultures to be their wives. They even had the nerve the multiply - have children - with these people! This broke Ezra. That the people would even consider marrying outside of their culture grieved him.
This is how many in America felt and still feel today about interracial marriages. Grieved. Some cite this very incident in Ezra to lend support to their beliefs and feelings about this being sinful. Yet, Ezra's reason for weeping is radically different. It was not the "difference" in cultural makeup that offended him because that did not and still does not offend God. God has called Israel to the nations and, thus, the nature of the calling of Abram entailed diversity. As the people came out of Egypt they did so as a multi-ethnic people with many Egyptians joining the exodus.
God is a God of unified diversity but not diversity at any cost.
The grief of Ezra centered around the fact that marrying outside of their culture brought with it their acceptance, even the worship, of the gods of these cultures. It was not intermarriage that grieved Ezra. It was the idolatry of the people tolerating the gods of the women they married. In so many ways this speaks to us regarding, not simply the nature and consequences of idolatry, but the way in which choosing spouses must be a discerningly spiritual and Christ-focused reality. The culture Christians should prioritize is the culture of Christ and the gospel.
In marrying another we marry everything about that person. Not simply their personalities, faults and families, but we also merge traditions, religious beliefs and practices. We often fail to consider this reality because other factors dominate our priority list. Things like their looks, place in life, motivation for success, their financial status and, in some cases, being in love with the idea of love and marriage. These things become the standard by which we determine our relationships and when they do they lead us to dark places.
Yes, we would want the prospective spouse to "know God" and to "go to church." We want them to be decent, and all around good and nice people. All too often, however, and for too many people, the fact of whether of not the person loves Jesus and is devoted to Him never is a standard of measurement. It is possible, therefore, to be married to a good person who is religious and faithful to church and, still, be unequally yoked! The standard for Christians is not whether or not people are religiously dutiful - the Pharisees were that and, yet, Jesus called them hypocrites full of unforgiven sin (Matthew 25). What is, or should be, the required standard is that which only Holy Spirit can produce: a life devoted to the pursuit of Jesus Christ. Flawed though they (and we all) may be, it is this passion for Jesus that will continue to shape your partner into Christ-likeness.
We should not, however, limited this concept of intermarriage to the institution of marriage. As Christians we are married to Christ and to involve ourselves in any activity that is married to the values of the world - marriage, business partnerships, jobs, etc - is to be guilty of the concept of intermarriage and spiritual adultery. Trusting in something other than the Lord for your life and hope or even accepting other beliefs as equally valid to the Bible, all of this is the sin of intermarriage with the broader culture and, therefore, idolatry.
Nothing short of weeping is acceptable because when Ezra wept, the people repented. There is a connection here. Our weeping screams to others that intermarriage is wrong, false and spiritually deadly. Only when this takes place can people be made to re-think and review their actions. Only by weeping for sin will some people repent of sin. The nation around us continues to mock God because the people of God refuse to weep and prove that Jesus is of unsurpassing worth.
Let me end with this thought which, by itself, begs further exploration:
I doubt that anyone truly repents of their sin who has not, first, wept over their sin
Thank you Pastor, this answers many questions I had during my studies in Ezra.