For a successful marriage there are basic things one should learn before signing up for the contract.
Marriage is the greatest institution on earth. It can either determine success or failure in fulfilment of destiny. Also God intends to use the medium of marriage to bring offsprings into the world that will fulfil his purposes.
It is no longer news today that more marriages are failing to meet up to God's expectations. Therefore, it is paramount that the right people be joined, armed with the right tools needed to accomplish God's purpose in their union.
When the right people are joined the first step to raising a Godly home is achieved. However, the right persons must also do the right things. If they don't understand how to manage their relationship effectively they will end up not fulfilling God's purpose in their marriage. They may truly love eachother but that alone will not guarantee a great marriage.
There are five things I have discovered a lot of couples lack that are basic for a fulfiled marriage. Most couples focus only on the material things leaving aside the things that matter most.
Before getting married arm yourself with these facts:
1. You and your partner must be born again.
2. You and your partner must have balanced spiritual lives. No backslidings. No secret sins.
3. You and your partner must understand the differences in the psychology of male and female.
4. You and your partner must understand the different personality traits(temperaments) and where you belong in oder to understand, accommodate and support eachother.
5. You and your partner must understand parenting/psychological changes that occur in children from chilhood, through adolescence to adulthood.

Armed with these few basics on which other things can be built on together with the Grace and providence of God, I believe every marriage on earth will be peaceful as well as fulfil God's purposes on earth.

Nice write up @op