The Bible teaches that there are three primary ways we grow: (1) being in God's presence through reading the Bible and prayer, (2) spending time with other Christians for fellowship and worship, and (3) encouraging one another to persevere in the faith and obey God. There are of course other ways to grow but this is a great way to begin. Let's look at these three ways and include some practical ideas.
Pray. When we pray our Father in Heaven listens (Jeremiah 29:12–13; 1 Peter 3:12; Hebrews 4:14–16). God listens to us in our time of need (Psalm 50:15), when we confess our sins (1 John 1:9), and when we make the effort to submit our will to His (Matthew 6:10; Luke 22:42). And God cares for our needs even when we are not praying, as the Holy Spirit is regularly praying for us, helping us in our weakness (Romans 8:26–27). How do we know all this? Because the Bible tells us so—the Bible is how God speaks to us today. "All Scripture is breathed out by God and profitable for teaching, for reproof, for correction, and for training in righteousness, that the man of God may be complete, equipped for every good work" (2 Timothy 3:16–17).
You can pray for new believers just as Paul prayed: thank God for making Himself known to them; ask God to grant them spiritual wisdom, insight into who He is, and knowledge of what He is doing; and pray that they are confident as a result of their hope in Jesus Christ (see Ephesians 1:15–23). You can also help new believers learn how to pray by praying with them and talking with them about prayer.
Invite. Any new believer can be swayed by the voices of the world and the lies of the evil one, resulting in a loss of confidence in Jesus (see Matthew 13:1–23). As such it is very important that all believers, especially new believers, spend time with other Christians. The Book of Acts records the behavior of the early church. In part, it says "And they devoted themselves to the apostles' teaching and the fellowship, to the breaking of bread and the prayers" (Acts 2:42). "And day by day, attending the temple together and breaking bread in their homes, they received their food with glad and generous hearts, praising God and having favor with all the people. And the Lord added to their number day by day those who were being saved" (Acts 2:46–47).
What might this look like for you? Invite new believers to join you for a Bible study or to go to church. Read a book of the Bible together and meet talk about it. Genesis, Luke, and Acts are helpful books to start with. Invite new believers to memorize Bible verses with you. Pray with them. Help them to discover the many ways to put into practice the truth that when we draw near to God He draws near to us (James 4:8).
Encourage. We all need to be encouraged. The Bible warns us that it is easy for us to go our own way even after we come to know Jesus (Proverbs 14:14; Hebrews 2:1–3; James 5:19–20). Jesus tells us that our lives will be hard, "I have told you all this so that you may have peace in me. Here on earth you will have many trials and sorrows. But take heart, because I have overcome the world" (John 16:33, NLT). But we are also told that friendship and fellowship are part of God's design for people as we can help each other up when we fall (see Ecclesiastes 4:10). How? The Bible tells us to love one another (John 13:34–25), care for each other (1 Corinthians 12:25–26), teach one another (Colossians 3:16), encourage others to persevere (Hebrews 3:13), and to pray for each other (James 5:16). Hebrews 10:23–25says, "Let us hold fast the confession of our hope without wavering, for he who promised is faithful. And let us consider how to stir up one another to love and good works, not neglecting to meet together, as is the habit of some, but encouraging one another, and all the more as you see the Day drawing near."
Need to get started? Read the Gospel of Luke and then the Book of Acts. From the Gospel of Luke, we learn that Jesus was born, lived a perfect life, that taught us how to live, performed miracles, died on a cross and was buried, and that He came back to life and He ascended to heaven. And the Book of Acts helps us to know how the early church responded to Jesus. It answers the question, "What difference should Jesus make in our lives?" These books discuss some of the foundations of faith and help us know how to encourage and help new believers. Genesis is also an important book to be familiar with as it tells of the creation of the world and sets the foundation for understanding the rest of the Bible.
Whatever you do, "let your speech always be gracious, seasoned with salt, so that you may know how you ought to answer each person" (Colossians 4:6). It is a long journey that we are on together. Each of us, one day at a time, is learning to stop believing in the ways of the world and instead discover and believe what God says to be true and what His will is (see Romans 12:2). So pray, invite, and encourage your friends and family who are new to the faith, and do so "with all humility and gentleness, with patience, bearing with one another in love" (Ephesians 4:2).