A Lamb… the Lamb… your Lamb. Exodus 12:3-5 The Lord’s instructions to Moses and Aaron were very specific. "A lamb" had to be chosen from among all the other lambs because of its visible perfection. There was no question about moral perfection, since it was meant to be a sinless sacrifice, and animals are not moral beings. In this way, a lamb could serve as a temporary substitute for a sinful person because it was a sinless, innocent creature. The lamb selected from the flock was, from that moment, called "the lamb." For three and a half days, the lamb was carefully examined to ensure no hidden defect, inward or outward, was found, which would make it unsuitable as a sacrificial substitute for the firstborn.
The Lord Jesus Christ entered the world and was hidden in relative obscurity for thirty years. The Lord Jesus Christ was sinless and perfect by nature. His moral standards are written on the hearts of humans made in the image of God. The sinless, eternal Son of God remarkably "was found in fashion as a man." He, who always was and always will be, the eternal God, became like us in our humanity, yet without sin, for He was spotless in His character. In this way, He could be a perfectly innocent substitute for us.
When He emerged from obscurity at His baptism by John in the Jordan River, John identified Him as "The Lamb of God which taketh away the sin of the world." He was observed from every angle during three and a half years of careful scrutiny. Some said, "Never man spoke like this Man." Others said, "We have never seen it on this wise before." Peter declared, "Thou art the Christ, the Son of the Living God." Pilate stated, "I find no fault in this, just Man." The centurion and those with him said, "Truly, this Man is the Son of God."
As the firstborn learned, "a lamb" became "the lamb" that would die as the substitute for the firstborn. He would recognize that this special little animal was going to die in his place even though it had done no wrong. Only because it was perfect would it die as an acceptable sacrifice. The Lord Jesus Christ was "A Lamb" and "The Lamb." Of that, there is no question. Now, we are able to move to the final and most important step. "Christ, our Passover, is sacrificed for us. Therefore, let us keep the feast." Every aspect of perfection God demanded is reflected in the perfection of the Lord Jesus Christ—the Lamb that God provided.
Christ's inward and outward perfections assure us that He alone is "The Lamb of God" who can satisfy the righteous demands of a Holy God on our behalf. God, in His grace, has made it possible for us to live forever because "A Lamb" that became "The Lamb" is now "Your Lamb." God is satisfied to accept each person who puts their faith in Christ as one who is "accepted in the Beloved," based on Him being the perfect substitute for me.