2 (I struggle that they may) reach all the riches of full assurance of understanding and the knowledge of God’s mystery, which is Christ, 3 in whom are hidden all the treasures of wisdom and knowledge. Jesus Christ is the key to all encouragement and love. That, I find, is often where people stop in their pursuit of Christ. He encourages them and loves them and they wonder if he has anything left to offer. He is safe there and does not seem to ask us for too much. Consider this: Christ is also the key to all the treasures of wisdom and knowledge. Everything you know and can know should be known through Christ. Paul is working hard for them, vs 1, so that they may reach all the riches of full assurance in their understanding and knowledge of this mystery that is the gospel. When you start doubting, wondering if it is really true, wondering if you did the whole faith thing right, when so many other ways seem so appealing and Christianity get...
The Cross of Christ, grace in reality, powerful to save and give us everything we need in every moment of life, all to the praise of His glory.