There is no more important decision after one has surrendered to Jesus.
In the Bible you will find the story of a wife being found for Isaac very helpful. You will also find chapters in Adventist Home or Messages to Young People, which will prove helpful.
Here are a few general things to consider:
Pay special attention to the first three questions. Depending on the answers to these three, you may not have to even consider the ones that follow for a few years since you are not ready to consider the "who to marry" question.
1. Do you know God's purpose for your life? Do you know what He kind of work He is calling you to? Until you know those answers it is very hard to know WHO God may be calling you to marry. Someone has said there are two great questions in life: 1. Where do I want to go in life (for the Christian what is God calling and preparing me for), and 2. Who do I want to go there with (note the right person is an individual who is wanting to go on the same journey you feel called to, or at least senses God's call and is prepared to unite in joining you in it). IF you can answer the "where" question, the "who" question is far easier to answer. Too many people answer the "who" question before they answer the "where" question. This can cause much frustration and sadness later. In my own mind, the great purpose in life is to know Jesus, to surrender to Him, and to devote one’s life to serving Him. Many attend church, but they haven’t come to see that their lives belong to God. For the person who recognizes that he or she belongs to God, it is important to marry someone who similarly recognizes God's ownership.
2. Are you of sufficient physical and emotional maturity to make such a decision. An 18 year old, for example, is going to change quite a bit in the next four years and doesn't even know what they will be like at the age of 22. What seemed perfect at 18, may seem awful four years later. It is best if you have completed a considerable part of your university experience before you get into serious discussions with a person of the opposite sex about marriage, for the university experience will greatly broaden your views of life and greatly augment your intellectual and emotional maturity. As a result it is only later that one can properly evaluate a potential marriage partner. For some people it may need to be even later if they are doing serious graduate studies. When in doubt it is always better to delay.
3. Are you of sufficient spiritual maturity to make a decision. If you have not fully surrendered your life to God, you probably won't ask God to lead you in this, or at the very least you will evaluate on the basis of human criteria instead of using Biblical criteria. If you have not surrendered your life yet to God, you are not ready to consider the "marriage" decision.
If you know WHAT God is preparing you for and sense your calling in life, and ARE of sufficient emotional, physical AND spiritual maturity, then you are prepared to consider the rest of the questions.
4. To what degree do you feel that God has specifically led the two of you together to serve Him in your marriage. In this respect what Muller says about knowing God’s will is very important.
5. Are you members of the same church? Don’t even consider marriage with someone who is not a Christian. You may not care today, but in most cases you will eventually, and the saddest people I know are the ones who didn’t care ahead of time, but later changed their mind, and find themselves in very unhappy marriages. The person should also be a member of your own church. If not, have them study what you believe BEFORE you get married. However a prior strong relationship with the Lord and with the church is a major strength for the future relationship.
6. How close are you in terms of lifestyle? The way you spend your time and money are important to consider. Granted marriage was given to help us overcome selfishness, however trend lines in this regard are worth considering.
7. Can each admit when they have made mistakes and ask forgiveness. One would assume that Christians could easily say “I am sorry,” and “forgive me,” words which are magical in a relationship, but the reality is otherwise. It is hard being married to someone who cannot—at least will not—ask forgiveness. Asking forgiveness is often learned, or not learned, through example at home growing up.
8. Are there similar energy levels. Some people are like the energy bunny, others need quite a bit of rest. Both groups include fine people, but significant differences in energy can challenge the relationship. Ambitions should also be similar, or at least compatible.
9. What are the family dynamics on each side? Can the families celebrate the union? If a family refuses to celebrate the union, are there valid reasons. What were the values of the respective families? Those values will often significantly impact the relationship in the future. What were the communication styles in the respective families? Do they communicate? Can they express affection? These styles definitely continue into the next relationship. None are necessarily bad, though there are exceptions such as an abusive home. Some people refer to the different languages of love and how each person communicates and responds to love in different ways—for example one person verbally expresses love, while another doesn’t express it verbally but gives many gifts. This is worth knowing about ahead of time. One should also consider how the respective families resolved their differences? Families tend to develop their own ways—patterns—of resolving differences. Some don’t, preferring silence, which can get a little old over time. Some do-loudly-but resolve them and everyone is happy. It has been suggested we all have two communication modes: the one we have when we are on our best behavior, and a backup mode one that comes out when push comes to shove-not necessarily so nice—which we learned growing up. You should also consider the kind of respect shown to the mom and to the dad. This is an important one, because if the guy didn’t see that his mom was respected and valued, he may not have the best foundation for showing respect to his spouse. The same is true for the wife so far as her respect goes for her father. Challenges in mentioned areas are not unchangeable life sentences, but they should not be minimized either. In some ways you ARE marrying each other’s family and are bringing the relational styles of your respective families to the marriage. Serious issues should result in serious counseling ahead of time.
10. How optimistic is the person? Optimism and hopefulness comes more easily to some than others. However, in my opinion, it is also a decision, and we can develop a more optimistic frame of mind by saying “yes” and “thank you” to God more often, which of course helps us develop a more confident belief that He is truly working for good in ALL situations somehow.
11. Can the respective parties make room for differing opinions and different rates of spiritual growth? Some individuals see every decision as a “yes” or “no” kind of decision—some would use the term “black and white”, regardless of what others say. Life isn’t always so simple and appropriate open-mindedness can make for a happier marriage.
12. Minimize the wonderful things ahead of time; maximize the little things. I am not negating the good things that attracted you, but they tend to be forgotten later and the little “We can change that later” things become all important. Don’t assume you can change each other AFTER the marriage. Warren says some good things in this regard.
13. Common interests are often cited as important ingredients of a happy marriage. The more things you enjoy in common, the more things you will enjoy doing together. The more time you spend together, the closer you will feel to each other. These commonalities will also help you weather relational storms easier.
14. To what degree are former associations having to change. Friendships are voluntary and are a good indicator of compatibility. If you have to change all of your friends to maintain the relationship, you should seriously pray about whether this is the ideal mate for you.
15. A suspicious, critical, spirit is also to be watched out for-everyone struggles with this some, but some people have more of a problem with this than others, and it can make for future unhappiness. Are there good reasons for the suspicions? Was this mode of thinking learned at home? Do the suspicians indicate an underlying insecurity? If it was a part of the home growing up, it may well continue into the new home. We are advised that this kind of spirit will destroy the spirituality of a church; it will also mar-perhaps even destroy—the happiness of your home. Life is too short to go through life being suspicious of everyone. If you want to experiment with this, spend a week criticizing each other and being suspicious of each another. Then spend a week affirming each other. See which mode results in a sense of feeling closer. Evaluate which mode results in a greater desire to love and cherish each other. I have heard it said that for every critical thing expressed to another person, ten positive things should be expressed.
16. How free is communication? Are your thoughts welcomed and seriously considered, or do you find your opinions being subordinated to the other? Do you find yourself “walking on egg shells” and avoiding certain subjects? This is a major red flag; it will only get worse after marriage. Open communication is an indicator of mutual respect.
17. Inordinate possessiveness can also be problematic. Some people feel good about themselves and can give much in the relationships, desiring the other person to succeed. Others are not as confident, and therefore struggle to allow the other person to have a “healthy” degree of freedom, sometimes find it impossible to allow any freedom. This is a serious red flag problem and you need to get counseling for this—if this is a serious issue, you should get out of the relationship as quickly as possible!
18. Are you able to study the Bible and pray together? This isn’t the easiest thing to do.
19. What are other people who know you both saying? The heart is deceptive above all things, and love can cause one to be blind. Asking the opinions of others is always a good idea. Many mistakes are made as a result of not seeking counsel from the godly people God has placed in our lives. Ask your parents what they think, but remember that non Christian parents cannot be looked to for godly counsel in the same way Christian parents can be looked to. Ask spiritually mature people what they think? Ask your friends who know you? Most of all ask God. Don’t minimize what is said, but also make sure you let God have the last word. Hudson Taylor, the famous missionary to China, was eventually happily married to Maria Dryer, in spite of a governess who was totally opposed to the marriage—friends actually secretly arranged for them to meet, at which time he immediately proposed. However, her parents' permission was sought and obtained prior to their getting married!
There is more I could share but these are a few things that come to mind.
There is something worse than being single, and something better than being single: being married. With the right person it is wonderful; with the wrong person it redefines the word “awful.” But after you are married it will be too late to change anything. That is why you should seriously consider the questions raised!
You will find that many—perhaps most—of the people who God used in a great way WERE married. Wonderful examples of much used couples include James and Ellen White, Stephen and Hetty Haskell and Minnie and Loren Sype.