Peace ali,
Listen, I only have one way to explain it from my viewpoint.
When I pray to God the Father, and ask him to forgive myself and the world for turning our backs on him, I feel it in my heart. Everytime I notice something of beauty, a cloud or perfect tree, I thank God for his creations he gave, in which we take for granted. And I feel it in my heart.
When I pray to thank Jesus for every hit, lash of a whip, for having to carry the very cross he was crucified on, and for spilling his blood; all for our sins. I feel it in my heart. Every time I ask Jesus to come into my unpure heart, and to save my soul. I feel it deeply in my heart.
When I pray to the Holy Spirit for guidance for life's decisions, and for protection of my family, I feel it in my heart.
Now it may seem that Im praying to three different entities for three different purposes. Yet when I pray asking each of the trinity for different things, the feeling in my heart doesnt change; its the same. It feels the same. As if the Three are answering my prayers, but one spirit fills my heart.
I know that this doesnt help you ali, buts its the best way I can explain it from my point of view. It's something you have to feel, then believe.
Peace and Godspeed to you all.