“rooted and built up in Him and established in the faith, as you have been taught, abounding in it with thanksgiving.”
The third statement about how God strengthens our faith is “established in the faith.
“and established in the faith
The word “established” means to make firm or make secure, to cause something to be known as certain–to confirm, verify. God is the cause of our certainty. God makes Christ known in such a way as to confirm its truth.
This word comes to mean increase in inner strength, resulting from greater firmness of character or attitude. It means to receive more inner strength, to be strengthened in one’s heart.
The adjective means stable, fast, firm. The New Testament uses it to confirm a word (Mark 16:20), proving the promises reliable (Romans 15:8), the testimony of Christ (1 Corinthians 1:6). Our salvation was confirmed or guaranteed to us by the apostles (Hebrews 2:3). Our hearts are confirmed by grace (Hebrews 13:9).
The saints will be confirmed by the Lord Jesus Christ (1 Corinthians 1:8) and by God the Father (2 Corinthians 1:21).
The word in this verse means to be made firm. God confirms us in the faith. That is, God makes us faithful disciples by strengthening us in Christ’s provisions. When we come to grasp who and what Jesus Christ is all about, God will establish us as faithful disciples.
as you have been taught
Teaching is the foundation for stability (Colossians 1:27-28, 3:16; 1 Timothy 2:7,3:2; 2 Timothy 2:2, 23-26). Teaching produces the three characteristics in the previous part of the verse. Their pastor was faithful in teaching them sound doctrine so that they can have spiritual stability.
We need a firm faith established by God in Christ.
Our repose is upon Christ; we are as unshakable as our Lord. Faith in God’s provisions in Christ is the cement for the building of our faith. That kind of faith can withstand any gale that may come. A strong Christian can withstand the shock of an enemy assault. In this case, the assault is the false teaching of the Gnostics. When we establish our footings in Christ, God gives us fixity. Our repose is upon Christ; we are unshakable as our Lord. His love for us never wavers or fails. Since it is God who strengthens our faith, we can face our problems with new power. Is your faith growing strong in your home, neighborhood, and work? God will strengthen our faith in these tests.