The two masters of which the Lord Jesus speaks are two gods, mutually exclusive, but not equally viable options.
The one true God, the Lord, gives you life and all that pertains to it, in both body and soul, here in time and hereafter in eternity.
The false gods of this world and all its wealth and power (which are legion) cannot give life nor preserve it, but bring death and despair.
You serve those false gods of wealth with much work and weariness, worry and fear, anxiety, anger and impatience. Your own hunger consumes you. You have no peace or rest. Whatever you do have (for this brief here and now) perishes — and you along with it.
To serve the one true God is quite different. To serve Him as your Master, your gracious and life-giving Lord, is to worship Him by faith and with thanksgiving. It is the prayer and confession of His Word, and the loving care of your neighbor within your own place in life.
This Lord God provides all that is needed for that which He has given you to do, and He provides you, by His grace, with far more than you deserve, need, or could ever imagine or hope for.
He does in fact provide for His whole creation — for the birds of the air and the flowers of the field; for sparrows and lilies, grass and trees and plants, animals big and small — the lions and the young ravens which do cry. He feeds them all and clothes them, and so He does for you, who are far more valuable and precious to Him. (Has He not purchased you with His own lifeblood?)
Indeed, He creates and preserves all of these things in His love for you, even as He feeds and clothes you with the plants and animals.
And yet, all of these things perish, whether for your clothing and food or otherwise.
Everything dies and wastes away. Birds fall from the sky. The grass withers and is burned up.
And you, O mortal man, O mortal woman, are like that grass.
The Lord your God gives and provides for your life in this world, but this life on earth is fleeting.
Why? Why bother?
He bothers for the sake of His love, because He is gracious and He delights to give good gifts.
He places the whole creation under the curse of death — on account of man’s sin — not to be vindictive, far less as a retaliation of “revenge,” nor as though He did not daily and richly forgive all sins; for He has, indeed, reconciled the world to Himself by His Cross and Resurrection, and, behold, He makes all things new.
But He teaches you His grace by His providential care, even as He calls you to repentance by punishing sin with death. He calls you away from the idolatry of this world, unto that life everlasting which is in and with Him in both body and soul.
You learn to know His care and loving-kindness in all His gifts of daily bread, but you also learn to look beyond those gifts to the Giver Himself, for the gifts come and go while He yet remains.
Dear child of God, dear brother and sister of Christ Jesus, your life is more than food, your body more than clothing. Your true body and eternal life are in and with Him, your Lord and Master.
See, not only does He clothe and feed your body and life here in time, for this little span awhile, but He Himself has become and is your Clothing, your Food and Drink, for both body and soul, both now and forever.
For He has perished in your place, bearing your sin and the curse of death in His Body of flesh and blood upon the Cross. There He was hungry and thirsty, naked and put to shame.
But God has raised Him from the dead and clothed Him with glory and honor.
This is the Mystery of God, which He gives to you by His ministers, the servants of His Word and stewards of His Gospel, who are fathers to you in His Name and stead.
Thus are you clothed with a garment that does not wear out; so that, even in death, you are not found naked, but are covered with Christ and all-glorious by His grace.
And thus are you fed with the Bread of Life, by which you live and shall not die forever. And you are given to drink the Blood of Christ from His Chalice at His Table in His Kingdom; so that you shall never thirst nor want for anything.
This Beauty of Christ is yours, and this Banquet of His bounty is already His Feast set before you, though it is given and received in the Mystery of the Cross, for now hidden in the midst of the darkness of death.
But by these gifts of His Righteousness — the Ministry of His Gospel of forgiveness — you have peace and contentment, refreshment and rest, and the Kingdom of God is yours in Christ Jesus, your Savior, in whom you have all things forever and ever.
In the Name + of the Father and of the Son and of the Holy Spirit. Amen.