You must learn to distinguish between religiosity and spirituality. Religiosity consists of taking part in many Christian activities. But to be spiritual is to allow the Holy Spirit to change our attitude (concerning everything) to the same attitude that Jesus had ( Phil.2:5 , "Have the same attitude that Christ had..."). We must never deceive ourselves that we are growing spiritually if that change of- attitude - towards women, money, people, circumstances, earthly honour etc., - is not taking place. Religious activity by itself will only make us whitewashed graves like the Pharisees. We must do everything to work out our own salvation from wrong attitudes, through the help of the Holy Spirit.
There is a vast difference between being religious and being spiritual. Under the old covenant, many who pursued righteousness became religious Pharisees. They were the greatest enemies of Jesus. Even today, it is possible to receive the truths of the new covenant in the spirit of the Law, and to become just religious. Then we will be the greatest enemies of God even today.
A person, who is more interested in an academic study of God's Word than in being filled with the Holy Spirit, and pleasing God, is in danger of ending up as a religious Pharisee, and not a spiritual Christian. In the Old Testament they were commanded to meditate on the Law of the Lord ( Psa.1:2 ). But in the New Testament we are to meditate on the glory of the Lord Jesus that we see in the gospels ( 2 Cor.3:18 ). The letter kills. The spirit gives life.
The kingdom of God is righteousness along with peace and joy in the Holy Spirit ( Rom.14:17 ). Religiosity may have a human righteousness, but it won't have peace and joy. There will be grumblings and murmurings, and fears and anxieties. True Christianity is a faith that brings fullness of peace - peace with God (a clear conscience concerning all matters), peace with men (as far as it lies with us), and peace within (freedom from anxiety and tension). It also brings fullness of joy - a life of overflowing thanksgiving and praise under all circumstances. We sing:
"He had no tears for His own griefs
But sweat drops of blood for mine"
That was how Jesus' lived. He never once felt sorry for Himself. Even when bleeding and carrying the cross, He told others, "Don't weep for Me" ( Luke.23:28 ). There was no self-pity in Him. He rejoiced constantly - even when badly treated by others, because He lived before His Father's face. That is how we must be too - with no tears for our own griefs.
Religiosity may have a lot of activity. But it is proud and it despises others. When we look down on others, or are proud of our righteousness, then we are religious not spiritual. (Humility is not spoken of much in the Old Testament, because it is a new-covenant virtue). We must ensure, that along with all our growth in Bible-knowledge, we are becoming spiritual and not just more religious.
Forgive everyone who has harmed you, set everything right with God and men, earnestly seek to be filled with the Holy Spirit, and determine by God's grace to walk the way of the dying of Jesus daily. Then you will become a spiritual man.