Trust is highly important in any relationship
Trust is the key to what they call a "perfect" relationship. In my opinion, not all relationships are exactly "perfect" because there is no such thing as perfection. In reality you want a happy relationship; The key to life is happiness.Having trust in a long distance relationship is extremely important! Having that much trust in someone is definitely a gift per say. Well, if you truly love that person, you should trust them either way. To build trust is kind of like a game. Trust is related to honesty. Ask questions to your significant other. Ask questions that are about trust and honesty, kind of like the ultimate love test!
It's also something you can do when you're Face Timing or Skyping him/her. When you're away from each other and you're doubting your trust with them, make a home made trust test and ask them questions that concern you. Joseph and I trusted each other since day 1 and we still do. We've never really had any trust issues in our relationship because we are 100% honest with each other.
The only advice I have for anyone in ANY kind of relationship is always trust your loved one and be 100% honest. It's better than lying.