What is God's way to come to full maturity in Christ, and how can I know it is the right way?

God Has A Way To Come To His Full Maturity, And It Is In The Bible.

At the start, it must be stated that there is no way that you can earn maturity just as there is no way you could have earned your initial salvation.  Jesus paid it all.  If you refuse to believe in Jesus and receive His salvation, then you will not be born into the family of God.  If you aren't born into God's family, there cannot be any maturity or fulfillment.  Once you are born again, if you refuse to walk in the Spirit, you will stay a baby in Christ.  If you walk in the Spirit, you are simply believing and receiving what Jesus already paid for.  You are not earning your way into the Kingdom of God.

God’s order for coming to Him will be the way and that order will be in place ‘til we all come to the full completeness of the likeness of Christ.  This is the duration.  God's order must be in place.

Ephesians 4:11 Till we all come in the unity of the faith, and of the knowledge of the Son of God, unto a perfect man, unto the measure of the stature of the fulness of Christ:

But how? Through the Church. God’s order. God ’s sent ministries. God’s called out people walking in God’s Spirit. 

You may have been dissatisfied with church.  You may have known, by the Spirit of God, that something was wrong or phony.  Perhaps you stopped attending.  Perhaps you knew, by the Spirit and by the Bible, that the Church has a certain order, and that order was not being followed.

Ephesians 3:10 To the intent that now unto the principalities and powers in heavenly places might be known by the church the manifold wisdom of God,