Feel a strong chemistry and attraction to your potential mate. In addition to being drawn to them as a human being and friend, you must be sexually attracted to this person. This is not being shallow; it fulfills a basic human need that contributes largely to our happiness. It's an element that simply must be there to support a loving marriage.
Realize you genuinely like the other person. It may sound obvious, but many couples justify long-term relationships though they constantly get on each other's nerves. Realize that a relationship with these types of irritations isn't likely to change.
Feel that you've truly spent time getting to know who the other person really is. Rather than basing this on a calendar length of time, base this decision on the quality and depth of your conversations and experiences with the other person in the time you've gotten to know them. Knowing you've seen this person at his or her most relaxed, at his or her best and worst moments, will allow you to see who the person really is, and will give you an idea of what the future with this person really holds in store.
Understand each other's spiritual side. Never underestimate this. A belief that God should be the center of your relationship can only be supported fully if your potential partner agrees. Make this a priority to discuss; it affects your lifestyle and your future family, should you decide to have one. Even beliefs that are agnostic or atheist should be discussed to ensure you are in agreement regarding your core beliefs.
Play together well, and often. You'll always have separate interests, that is natural, but you must also know how to enjoy leisure time together. This is more than sex, like sharing mutual interests or opening up to exploring things your partner loves. It's been said that couples who play together will stay together.
Feel that you share long-term goals for what you want out of your life. This can range from where you want to live, to what your individual career goals are, to if, and when, you'd like to have a family. Anything that you deem important to you should be discussed with your potential spouse, and visa versa.
Know inside that you're ready for marriage, the commitment it holds, and that you're ready to marry this person. When this feeling arises and gives you confidence, security and happiness in your relationship with this person, you should feel great knowing you've been given a gift that few appreciate. Discuss your wishes to marry with your partner openly and fully before taking the big leap.