You ask the question of the ages: "Why would God [insert question here]?
As humans, we are not meant to know certain things until we realize, "Wow, I'm so glad that happened to me back then ... because it brought me to exactly where I am NOW!"
When your soulmate entered your life, he may have made you feel so special and loved, while asking for nothing in return except for your love. It may have felt as if you had truly found your heaven on Earth. Life couldn't be more joyous or full of hope and excitement. And then the unspeakable happened ... he died out of the blue, and you were left with your shattered dreams of a future together, replaced by the nightmare of him being gone and your desire to follow him to the ends of the Earth.
But you still have a very important journey to complete going forward, my friend.
First, remember that you will NEVER be without your soulmate. He has now formed an integral part of your heart, and he will be there for you whenever you need him. Just let your mind be quiet and listen closely for his voice and guidance.
Second, realize that there has always been an epic purpose for your own life. Your soulmate touched your life so deeply and completely that you just KNEW your paths were meant to cross. He then left you stronger and wiser than you ever thought possible, and his comforting presence will remain with you forever. Use his gift of unconditional love for the power of good ... always. Look at all the ways that YOUR love is meant to heal and improve the lives of others going forward. Your soulmate taught you how wonderful it felt to have someone truly love you unconditionally, his loving arms wrapping around your trembling soul until you felt 100% safe again. That is the unconditional gift of his love that you simply MUST pay forward in gentle ways during your own lifetime: to a crying child, to an angst-ridden teenager, to a lost and homeless older soul living on the street, to a helpless animal caught in a hunting trap.
Third, you asked whether or not when you die, you and your soulmate will be reunited again. Well, there is no need for a reunion because your beloved is already wrapped around your soul like a warm blanket, just like your love will envelop his heart forever and always. Now, you just need to learn how to live your life on a day-to-day-basis without his physical presence, knowing that the most important part of him has now become a part of you.