Society in Australia and across the Western world has, since the 1960s, moved from a traditional understanding of marriage and family to a “whatever feels good, do it” attitude.
When God said “You shall not commit adultery”, He meant it. What is implied is something much better: God-honouring marriage, Genesis 2:24, 1 Corinthians 7:2, Hebrews 13:4. The relationship between husband and wife is analogous to that between Christ and the Church, Ephesians. We are united to Christ and the Holy Spirit lives in us as His Temple, 1 Corinthians 6:15-20. How can we then be united to any person to whom we are not married?
There is no marriage service in the Bible, but every culture has a way of telling which people are married and which are not, though only the Bible has a monopoly on God’s definition of marriage.
We must not follow the world’s pattern, but be transformed to follow God’s pattern, Romans 12:1-2. As well as rejecting the bad, we must put on the good, Philippians 4:8-9. What the eye sees can never satisfy, Proverbs 27:20. Instead, we should guard our hearts, control our bodies and watch our paths, Psalm 119:9-11, praying continually and relying on God’s Holy Spirit, 1 Thessalonians 5:17.
It is clear that we are not able to live our own way and be God’s. When we become one of His and our behaviour is put in the past. We are washed and justified and continually changed into the likeness of Jesus. If we do not believe that God makes these changes in us, we have no message of hope to hold out to others and are trusting in our own goodness, which can never save us.