You can have trust and faith but ultimately you've got to wait on people to prove their sincerity and decency through their actions. The promises of others are no more a certainty than a cloud is a guarantee of thunder.
Never give up on people you love but it's not your responsibility to carry them either. A relationship isn't a rescue raft, it's a partnership. Both parties must make an effort to keep things going or else one is going to be brought down by the other.