It's just a knowing. An experience within that for each individual is as unique as one's own DNA. Think in terms of tears streaming, a great longing to near their presence, it's just as easy as something feeling in harmony. No matter how many doubts present themselves, they're easily resolved with a thought, an occurrence or a series of events that will put all your doubts to rest.
I've had great difficulty with accepting the fact that we all need our own personal connection to that which is best for our unique paths. Allowing Love & Light for other people's connections to their respective Gurus is difficult when one thinks of one's own Guru as a Satguru (Perfect Master). Nevertheless, more connections with other devotees of other paths has opened me up to that reality.
I wish you well. Just keep your heart open & your desire, longing strong. It will happen & you will know. In your heart!