Religion would say that we measure it by church attendance, financial giving, bible study, and prayer. Those might provide us with concrete methods of measurement, but if we use them as our criteria, even the Pharisees would have a dynamic spiritual life. We're called to something much more significant than just a few religious rituals.
The true rule of measurement should be Jesus' teachings. To him, the greatest commandments were summed up in two: Love of God and love of neighbors. Loving God is pretty intangible; it's not something we can see. We can't measure it by how often, loud, or passionately someone sings songs of praise. We can't measure it by how frequently someone attends services at a church. My knowledge of Scripture is no evidence of my love for God. All of the typical measurements that we like to fall back on do not really tell us if we are growing spiritually.
The Apostle John explained how we love God. He said that if we claim to love God but do not love the people around us, then we are lying (1 John 4:19-21). Our love of God is shown in only one legitimate way, and that is by loving people. If our love for our neighbors does not increase, then we are not loving God.
Unfortunately, we often make the mistake in thinking that loving people is telling them the truth. That's not the case. We need to be prepared to let them know the truth when they ask about our love, but we love whether or not we get an opportunity to preach the message with words.
Our vision at Riverside is to be a real, authentic community in Christ, have a passion for Jesus and His work, and to love people around us in tangible ways. It is our hope that through doing this, people’s lives will be transformed and God will add to our number. It culminates in us loving God. If our life together and our passion for Jesus do not lead to us loving people, then all of the religion is meaningless.
The measurement of spiritual growth is not measured in how excited we are, in how knowledgeable we are, in how devoted we are, or any other religious criteria; it's measured in whether our love for others is increasing. Are we spending more time now loving our neighbors, co-workers, and friends? Are we looking for opportunities to share God's love by helping meet people's physical needs throughout the day? Are we encouraging others? Those are the true measurements of spiritual growth.