For [of course] every house is built and furnished by someone, but the Builder of all things and the Furnisher [of the entire equipment of all things] is God. —Hebrews 3:4
God is the Master Builder. Jesus is the Chief Cornerstone. God is the one who has to build us and equip us for the work of the Lord Jesus Christ. In Philippians 1:6 the apostle Paul writes to assure us, He Who began a good work in you will continue until the day of Jesus Christ [right up to the time of His return], developing [that good work] and perfecting and bringing it to full completion in you. What he was saying to us is simply this: “It was God who started this work in you, and it is God who will finish it!” That means we should leave God alone to do His work. We need to stay out of His business and mind our own.
There are certain things only God can do. We are to do our part and let Him do His. We are to handle our responsibility but cast our care on Him. We are to confess our sins and failures to the Lord, confident that He will forgive us of those sins and failures and cleanse us from all unrighteousness, as He has promised in His Word (1 John 1:9). We are to trust to Him the job of perfecting us for the work He has for us to do in this life. That takes the pressure off of us, which relieves us of the worry and anxiety we feel so often as we try to perfect ourselves.