There is a sacredness in tears....They are the messengers of overwhelming grief, of deep contrition and of unspeakable love.

This quote is saying that tears are special and have a powerful meaning behind them. Tears usually come from an emotional place, they could be a sign of hurt, sorrow and regret, or they could be a sign of feelings that are difficult to express with words, such as love and joy. Essentially, the quote is saying that tears convey powerful messages that are hard to articulate in any other way.