Col. 2:6-7 And now, just as you accepted Christ Jesus as your Lord, you must continue to live in obedience to him. Let your roots grow down into him and draw up nourishment from him, so you will grow in faith, strong and vigorous in the truth you were traught. Let your lives overflow with thanksgiving for all he has done.
Notice, accepting Christ as our Lord is not the end; rather, it's just the beginning. We must continue to live in obedience to Him. Jesus cannot be our Lord without our being submissive to Him and obedient to Him.
We are to let our roots grow down into Him and draw from Him what we need to grow in faith. You will find nothing helpful to your spiritual grow outside of Christ. In Him we find all that we need. The closer we live to Him, the stronger and healthier our faith will be.
When we live in Christ and let Him feed our souls, we become strong and vigorous. The reason why so many of us are week and anemic is that we do not take seriously our need to let the Lord feed our souls. We don't bother with spending time in fellowship with Him in the Word and in our prayer closets. We do not build on the things we have learned; we tend to want to coast our way to heaven. And, it simply does not work.
As we live in Christ, we should overflow with thanksgiving for all that Christ has done for us. Daily we should express our gratitude to Him for all He has done, is doing, and will continue to do in us.