As they say in the cliches, you can lead a horse to water but you can't make it drink. I think this is true in relationships too. You can lead the other person along the path that promises happiness, but you can't make them take the next step.
As they say in cliches, if you truly love someone, you will let them go and if they return to you, you were truly meant to be together. When that horse you lead to the water, doesn't drink... you have to let them go and find their own way to the water (even if they never do).
I've trusted my heart to these cliches recently... I hope it works... if not, look for a cry for help, readers. pray, pray, pray