how would we know if our loved ones who we have lost to death are still with us ?
Our departed friends and loved ones remain in our hearts. That is how you know they are with you. We are not mere bodies, the product of minerals and chemicals: “tat twam asi” — we are THAT — We are waves of the Infinite Ocean. Those other “waves” with whom we have a heart connection remain part of us. As we grow spiritually our connection with the Ocean of Life steadily expands until we are One with God and all creation.
Swami Sri Yukteswar (Yogananda’s guru) explained to Yogananda that when we leave the body of a given incarnation we may meet husbands, wives, friends, children, etc. of past incarnations. We do so that we might gradually love all as our very own. Buddha, too, said that the reason to love all is that at some point in time we have known everyone.
Yes indeed, therefore, your soul-friends live on. Krishna assures us (in the Bhagavad Gita) that the soul never dies. It is eternal. In fact, it is taught in all faith traditions that prayers of comfort and love (but without grief or attachment) offered to the souls of departed loved ones can help them very much. Why is this? Because bereft of the human body and to the degree of their prior identification with the body, they are a bit lost and unable to help themselves (that is, to stay awake and self-aware). They might feel grief or regret. Your prayerful message of love will be comforting. OK?
Blessings to you,