Those are beautiful parables.
Reason for those parables:
Luk 15:1-3 NKJV - 1 Then all the tax collectors and the sinners drew near to Him to hear Him. 2 And the Pharisees and scribes complained, saying, "This Man receives sinners and eats with them." 3 So He spoke this parable to them, saying:
Parables outcomes:
1)
Luk 15:5, 7 NKJV - 5 "And when he has found [it], he lays [it] on his shoulders, rejoicing. ... 7 "I say to you that likewise there will be more joy in heaven over one sinner who repents than over ninety-nine just persons who need no repentance.
2)
Luk 15:9-10 NKJV - 9 "And when she has found [it], she calls [her] friends and neighbors together, saying, 'Rejoice with me, for I have found the piece which I lost!' 10 "Likewise, I say to you, there is joy in the presence of the angels of God over one sinner who repents."
3)
Luk 15:23, 27-28 NKJV - 23 'And bring the fatted calf here and kill [it], and let us eat and be merry; ... 27 "And he said to him, 'Your brother has come, and because he has received him safe and sound, your father has killed the fatted calf.' 28 "But he was angry and would not go in. Therefore his father came out and pleaded with him.
The purpose of the parables was simply to help understand the value of the souls to heaven, to the point they rejoice when they repent. The
tax collectors and the sinners that came to him had a repented heart.
The point was to show the Pharisees that their behavior was not reasonable, or right, and they did not know the heart of God.
We can find minor points or read more into the parables that its purpose, and they may even be more hidden points, but the point Jesus is trying to make is explained in the text itself, except for the Prodigal son, but the previous parables and who they were addressed to can give you the hint.
The sheep and the coin do not have understanding of them being lost, and they do represent the sinners, but that's not the characterization of the sinners intended in the parable. In fact, the sinners in Israel knew what they were doing, they had plenty of synagogues preaching Moses, and a whole culture built around that. The idea is the rejoicing of the one that finds the valuable thing and brings it back to where it belongs, which is God and his friends (angels) rejoicing because of souls coming back. The point is again the Pharisees and scribes not understanding God's heart.
The Prodigal son parable was also addressed to the Pharisees, and it is more realistic. The new character is the jealous son. It was intended to reveal the wrong attitude of the Pharisees towards repented sinners.
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