The inworking of God the Spirit in the Old Testament
The Holy Spirit was present in the Old Testament working on mankind’s hearts (Gen 6:3; Psalm 51:11) to convict them of sin and unrighteousness. He was in effect in both testaments convicting men of sin.
Even though the manifestation of the Spirit in its fullness was only in the NT, the Spirit was still there in the OT working on men’s hearts to keep the law (Psalm 40:8). A heart experience was still required in the OT (Deut 6:4-6; 10:16; 30:6).
When the people tried to keep the 10 Commandments themselves with out the aid of the Holy Spirit, God told them (Deut 5:28, 29) O that there was such a heart in them that they would keep my commandments. In other words they had heart problems. They made their hearts as an adament stones lest they should hear the law (Zech 7:12).
Everyone has enough light from heaven to be saved (Romans 1:20; John 1:9; Titus 2:11). God considers the background of where we are born when he writes our name in the book of life (Psalm 87:4-6). When we don’t know any better he understands and does not count sin to us but if we know better that’s a different story (Acts 17:30;Hosea 4:6).
When the heathen do right even though they don’t have the Bible, God says it shows that the Spirit of God has worked in their heart (Rom 2:12-15).
When we get to heaven there will be many there who have never heard the Gospel Story (Zech 13:6). Jesus takes care of those sins of ignorance (errors) himself (Hebrews 9:7). It is only when the sins of ignorance are known that it becomes sin (Lev 4:2,3-12 Priest, v13-21 Whole congregation. 22-26 Ruler, 27-35 Common people).
Notice that when the the sin comes to their knowledge or remembrance or is known – then they bring the offering) SOOOOOOooooooo…. The Holy Spirit was working in the OT but they rebelled and vexed His Holy Spirit (Isa 63:10;Gen 6:3).
The Holy Spirit preached to them through the preachers and prophets (1 Peter 3:18-20). The manifestation of the Spirit in it’s fullness in the OT was only occasional and on few individuals (Numbers 11:26,27; PP381; 1 Samuel 10:6-10).
In the NT there was an outpouring of the manifestation of the Spirit (Acts 2, 10, 19). This was not just conversion (John 3:5, 8; Rom 8:9) but the fullness or the infilling that was now to all the believers where he made His abode with them (John 14; 16, 17; 2 Cor 6:16; Acts 2:38; Acts 19:2; Eph 5:18).
In the olden days the Spirit filled the prophets – now he fills all the believers controlling them (Joel 2: 28, 29-32; Prophesy – Acts 2:16-21 fulfillment) . The idea of being filled with the Spirit is a NT idea (Acts 2:4; 4:8, 31; 9:17; 13:9. 52; Eph 3:19; 5:18) .