Yes you can say you trust that person in your life over saying you love that person in your own life. But how can you trust if you don't love? Or have love in your own heart? If you can trust that person and say that with fullness in your heart, then you can love.
Yes if its about platonic/ filial relationship. But in a relationship beween partners "I love you" it is. Cause trust is a component of that love you have for your partner. If you didn't trust him/her how could you have fallen in love. So whether it's trust,faith, or the likes that "I love you" sums it up