Although it is certainly possible for some friendships to get along without a full level of trust
between both parties, it will necessarily be harder to maintain the relationship. Once trust has broken down to some degree with a friend, then it will not be easy to earn back. All that you can do is to allow the trust to develop over time. Whatever caused the mistrust in the first place will eventually recede in importance that, in truth, it may never be forgotten. Some friends will make an active decision to forgive one another following a breach of trust, and forgiveness
can definitely help to speed up the process, however. When trust is breached multiple times, it is likely that the two friends will end up deciding to dissolve their relationship, which may be the right course of action in these circumstances.