Answer: You measure the acceleration by evaluating your connection with the group. You don’t have anything else. This is why one common soul was broken into many souls – so you would have a means to change, a place to work and make efforts, so you could assess how far or close you are to them – and not simply to people, but to their desires to reveal spirituality, the Creator. You check whether you are among these desires, together with them, so that in the right connection, in the mutual guarantee between you, you will reveal the Creator.
Therefore you can assess your spiritual state only in relation to these desires of your friends – how close are you together with them to the upper world.
Question: But where is the acceleration here? How can it be measured?
Answer: From one day to the next, from one minute to the next, you evaluate this connection. There is a distance between you and others, and you assess whether it is becoming reduced or not, how, with constant speed or with acceleration. Acceleration is speed that increases at every moment.
From the 2nd part of the Daily Kabbaalh Lesson 7/22/11, The Zohar