Is there scriptural basis for spiritual 'growth'? In my denomination from time to time I hear about spiritual 'growth'. 
I get quite confused about it. It seems to me that Jesus taught to love people, give what we have to the poor, pray for people, cast out unclean spirits, bless people who curse us, give the other cheek, do not call people things because words have a lot of power (physical wounds other people can see, but internal/psychological wounds generally go by without the knowledge of others even for decades or a lifetime), give to whoever asks, lend without asking back, do not serve money, do not be anxious, love God and others.

2 Peter: 5.For this very reason, make every effort to add to your
faith goodness; and to goodness, knowledge; 6and to knowledge,
self-control; and to self-control, perseverance; and to perseverance,
godliness; 7and to godliness, mutual affection; and to mutual
affection, love. 8For if you possess these qualities in increasing
measure, they will keep you from being ineffective and unproductive in
your knowledge of our Lord Jesus Christ.

It seems to me that God does indeed cleanse people inward. People who come to Jesus stops cursing,  cheating, being immoral, starts loving God, etc. I believe this is the work of the Holy Spirit. 
Also there are spiritual gifts that God gives to people (word of wisdom, word of knowledge, faith, gifts of healings, miracles, prophecy, distinguishing between spirits, tongues and interpretation of tongues) which it seems are all for serving one another.
And finally the fruits of the spirit:
Charity (or love), joy, peace, patience, benignity (or kindness), goodness, long-suffering, gentleness, faithfulness, self-control.
Is there such a thing as spiritual growth, if so, what is it and what is the scriptural basis for it?
Spiritual growth, or growing spiritually, is the core of our Christian walk, where the Spirit works in us and transforms us as we understand more of His Word and live according to the Word, and as a result we become more and more like Jesus.
Here is a good article on spiritual growth:
https://biblereasons.com/spiritual-growth/
Often, different spiritual life stages are used to summarize/categorize where people are in their Spiritual journey:
5 Stages of Spiritual Growth
Stage 1, The Spiritually Dead
Stage 2, The Spiritual Infant
Stage 3, The Spiritual Child
Stage 4, The Spiritual Young Adult
Stage 5, The Spiritual Parent
One example is in 1 Corinthians, where Paul called the Corinthians infants in Christ.

1 Corinthians 3:1-3
Brothers and sisters, I could not address you as
people who live by the Spirit but as people who are still worldly–mere
infants in Christ. I gave you milk, not solid food, for you were not yet ready for it. Indeed, you are still not ready. You are still
worldly. For since there is jealousy and quarreling among you, are you
not worldly? Are you not acting like mere humans?

And there are many other verses talking about the spiritual growth -

2 Peter 1:6 and in your knowledge, self-control, and in your
self-control, perseverance, and in your perseverance, godliness,
2 Peter 3:18 but grow in the grace and knowledge of our Lord and
Savior Jesus Christ. To Him be the glory, both now and to the day of
eternity. Amen.