Wolfgang Pauli was an Austrian theoretical physicist who won a Nobel Prize in 1945 for what is called the “Pauli exclusion principle.” Though his research was done at the molecular level, his work laid the foundation for this popularized law: Two different objects cannot occupy the same space at the same time.
Pauli’s principle can help us think about a corresponding spiritual law: a Christian cannot be moving forward toward maturity and backward toward immaturity at the same time. Many Christians worry about the possibility of falling away from the faith, about losing their salvation. But one simple test will relieve those fears: Are you pressing on toward the high calling of God in Christ Jesus? That is not to say our salvation is dependent on our pressing on. Rather, it means that our hunger to grow in Christ is a sign of our genuine spiritual state. If we are moving forward, we cannot be moving backward.
If you know you have believed on the Lord Jesus Christ (Acts 16:31), make sure you are continually pressing on toward maturity in Him.