The Use of the Term “συνιέναι” in the New Testament
The term to understand (“συνιέναι”) means to bring together, and therefore means to understand something. In the New Testament, the term to understand (“συνιέναι”) always refers to spiritual understanding.
1. The Words of Jesus and Understand. Jesus traveled to Jerusalem with His parents. When they left to return to Nazareth, He stayed behind in the temple. He was sitting in the midst of the teachers, both listening and asking them questions. All who heard him were amazed at His understanding (“συνέσει”) and His answers. When His parents came looking for Him, Jesus asked His parents: “Did you not know that I had to be in My Father’s?” (Luke 2:45-49). His parents did not understand (“συνῆκαν”) the word (“ῥῆμα”) which he had spoken to them (Luke 2:50; compare did not know (“ἠγνόουν”) the word in Luke 9:45; Mark 9:32; see also “not know (“εἰδότες”) the Scriptures–Mark 12:24). Therefore, in this context, the parents of Jesus did not understand the Scriptures indicating He must be in His Father’s house, speaking the word to all who would hear Him there, amazing the crowd with His understanding (“συνέσει”).
2. Hearing and Not Understand. Jesus spoke in parables so that seeing, they would not see, and hearing, they would do not hear (“ἀκούουσιν”) nor understand (“συνίουσιν”) (Matthew 13:13, 14). Jesus then revealed that the heart (“καρδία”) of this people has become dull (“ἐπαχύνθη”). They also must understand (“συνῶσιν”) in their heart; then they would return to the Lord, and He would heal them (Matthew 13:15; Mark 4:12: Acts 28:26-27). Therefore, in this context, understanding occurs in the heart, so that once a person understands the message of Jesus, then that person would return to the Lord and He would heal that person. In passing Jesus linked “you will see” (“βλέψετε”) with you will not (“οὐ μὴ”) know (“ἴδητε”).
3. The Word of the Kingdom and Understand. Jesus explained some of the violence perpetrated upon the kingdom of God in the parable of the sower and seed (Matthew 13:19). When a person hears the word of the kingdom, but does not understand (“συνιέντος”) it, the evil one comes and snatches away the seed sown in the heart. Therefore, we see that the term understand here means to understand the spiritual significance of the gospel. Because the unbeliever did not understand the gospel, the devil then snatched the seed from that heart.
4. The Seed Snatched away and Understand. God granted to the disciples to know (“γνῶναι”) the mysteries of the kingdom of God, but to the rest they heard parables, so that seeing they may not see, and hearing they may not understand (“συνιῶσιν”) (Luke 8:9-10). Jesus proclaimed that some the seed which fell beside the road. When people hear the word, but do not understand (“συνιέντος”) the word, then the evil comes and snatches away what was sown in their hearts. (Matthew 13:19–see The Kingdom of God Suffers Violence). Therefore, in this context, the term “understand” occurs in the heart, so that they return to the Lord and He would heal them. In this case, the evil one snatches away the seed sown in the heart because the hearer did not understand in the heart, and so the hearer never understood the Gospel of Jesus Christ, never returned to the Lord, and was never healed. Therefore, the seed which fell by the way indicates those people were never saved, because they never understood, they did not return to the Lord, and were never healed.
5. Hear and Understand. Jesus summoned a crowd to Himself and commanded them: “Hear (“Ἀκούετε”) and Understand (“συνίετε”) (Matthew 15:10: Mark 7:14). After Jesus commanded the crowd to hear and understand, His disciples came to Him asking for an explanation. Jesus then said “Now are you without understanding (“ἀσύνετο”)?” (Matthew 15:16: Mark 7:18). Jesus continued with “You do not mind (“νοεῖτε” that all that goes into the mouth into the stomach passes into the intestines and cast out? (Matthew 15:17). Jesus then explained that evil comes out of the heart, not the stomach (Matthew 15:18-19). This exchange shows that even the disciples did not have spiritual understanding of the words of Jesus. Therefore, the term understand means to hear and then understand the spiritual significance of His teaching about defilement.
6. The Hardened Heart and Understand. Jesus confronted His disciples about their lack of understanding (Mark 8:17). They failed to understand that the teaching of the Pharisees produced a spreading evil, like leaven. Jesus said: “You do not mind (“νοεῖτε”) nor understand (“συνίετε”)?” Therefore, the term understand is not the same as “mind” (“νοεῖτε”). In this context, the term understand applies to spiritual understanding concerning the leaven of the Pharisees. Jesus continued and warned them about a hard heart because they had eyes that did not see and ears that did not hear. He reminded them of the miracles of the loaves and fishes. Jesus then said: “Do you not yet understand (“συνίετε”)?” (Mark 8:21). Therefore, in this context, to understand means concerns learning the spiritual significance of events, by using your eyes and ears to understand spiritual truth beyond the physical miracle.
7. Opened Their Minds To Understand the Scriptures. Jesus opened the mind (“τὸν νοῦν”) of the men on the Emmaus Road to understand (“συνιέναι”) the Scriptures (Luke 24:45). Notice the connection between mind (“νοῦν”) and understanding (“συνιέναι”). For the purposes of Exegetical Psychology, only when Jesus opens the mind of believers can they begin to understand the Scriptures. Furthermore, the capacity to understand the Scriptures comes from the mind opened by Jesus.
8. He Was Supposing That His Brethren Understood. As Stephen preached his last sermon before the crowd which martyred him, he spoke about Moses. Moses assumed that his brothers would understand (“συνιέναι”) that God through his hand would give salvation to them; but they did not understand (“συνῆκαν”) (Acts 7:25). Moses assumed that the people held captive in Egypt would have spiritual insight into God’s plan for delivering them, but the people had no such understanding. In this case, to understand (“συνιέναι”) means to be able to grasp the spiritual plans of God for deliverance.
9. Knew God and Understand. Paul described in detail the depravity of man in knowing (“γνόντες”) God, but man did not honor God or give thanks, but the people became futile in their reasoning (“διαλογισμοῖς”), and was darkened their without understanding (“ἀσύνετος”) heart (Romans 1:21). Therefore, in this context, hearts can become without understanding, even though people may know God through the creation, but suppress that knowledge in sin.
10. Improper Things and Without Understanding. God gave people over to a depraved mind, so that they became, among other things, without understanding (“ἀσύνετος”) (Romans 1:31). In this context, God gave over sinful people to many improper things, including the lack of spiritual understanding.
11. No One Understands. Both Jews and Greeks are under sin, because there is none who understands (“συνίων”) (Romans 3:11). Therefore, in this context, God indicts all men for their failure to understand the spiritual things concerning God.
12. A Nation without Understanding. Paul, quoting Moses, said that God will use a nation without understanding (“ἀσυνέτῳ”) to anger Israel (Romans 10:19). In this context, the nation was without spiritual understanding of God, but they found God.
13. Not Heard Shall Understand. Paul explained that he did not build upon another man’s foundation, but fulfilled the prophecy: “They who had no news of Him shall see, and they who have not heard shall understand” (Romans 15:20-21). In this context, Paul spread the Gospel of Jesus Christ to new places, so that the people there, often Gentiles, would hear and understand (“συνήσουσιν”). Therefore, in this context, the people heard the Gospel of Jesus Christ and understood, indicating they were saved. Understand here means salvation for the hearers.
14. Read and Understand. Paul wrote about the mystery of Christ (Ephesians 3:4). He told the Ephesians that reading they can mind (“νοῆσαι”–notice the aorist infinitive) his understanding (“σύνεσίν”) into the mystery of Christ. Therefore, in this context, the saints may mind Paul’s understanding of the mystery of Christ, particularly as it applies to the Gentile readers.
15. Unthinking and Understand the Will of God. Paul explained that the wise redeem the time, because the days are evil (Ephesians 5:16). He warned believers not to be unthinking (“ἄφρονες”), but understand (“συνίετε”) the will of the Lord (Ephesians 5:17). Therefore, in this context, if one is unthinking, then one will not understand the will of the Lord. But if one thinks, then they will understand the will of the Lord. Furthermore, Paul commanded believers to understand the will of the Lord, which means they must be filled with the Holy Spirit (Ephesians 5:18).
In all the examples above, understanding always refers to spiritual understanding which takes place in the heart. Without understanding, people do not know or do the will of God. Jesus commanded people to hear and understand His word, but the hearts of people had become dull; indeed, the hearts without understanding were darkened. As part of salvation, God opens the heart, and the person instantly understands the Gospel of Jesus Christ for salvation. People come to Jesus, and He heals them instantly at the moment of salvation by faith alone.