Your spiritual growth is through a personal relationship with God in Christ. Don't be satisfied to remain where you are without growing in Christ. "But grow in the grace and knowledge of our Lord and Savior Jesus Christ" (2 Peter 3:18). That statement summarizes your spiritual growth in Christ.
Your spiritual growth is through the word of God in the Bible. A proper diet is necessary to maintain good health. Likewise, feeding upon God's word in the Bible is necessary for your growth in Christ. Knowledge should lead to growing in the grace of Christ, which is the unmerited favor of God.
Your spiritual growth strengthens your faith in Christ. So then faith comes by hearing, and hearing by the word of God (Romans 10:17). We believe what we know is true. Increased knowledge of Christ should lead to increased faith and assurance in Christ. That is growth in grace. It's growing in the grace and knowledge of our Lord Jesus Christ.
Your spiritual growth is through life situations. God allows us to be in situations beyond our ability, that we may not trust in ourselves but in Him. Our impossibilities are always His possibilities. With God all things are possible. Jesus said, "For without me you can do nothing" (John 15:5). That lesson leads us to spiritual growth in the grace of Christ, as we trust Him in all of life's situations. Oh for grace to trust Him more!