To build upon what J. Jump said, it is a problem with the way that salvation is taught today.
The Bible supports OSAS specifically, but then goes on to give warnings about faithful living, etc.
Most churches that see the truth of OSAS fail to teach the warnings and instead teaches either "it doesn't matter how you live" or "if you're really and truly saved [an idea not found in the Bible] then you won't do that anyway, so why teach it".
Jesus came as prophet.
Today he's our high priest.
One day, he will be King.
Although it would behoove us greatly to look at our relationship to him as our high priest, we also need to look at what it means that he will one day be King.
For a picture of that, look at the picture that is given in the OT: Saul was king, David was anointed king. David did not ascend the throne immediately. Instead, Saul finished out his rightful reign as king, while David surrounded himself with faithful followers who put themselves in hardship and danger to support him. Then, when Saul died, David assumed the throne, those who had been faithful were given positions of honor and glory, and everyone else was killed. (OK, OK, everyone else became subjects.)
A picture of the coming Kingdom. Satan is the god of this age. Jesus is the god of the age to come. (The picture of Saul and David.) We can choose to be faithful now, and have glory and honor in the coming Kingdom (the hard way), or we can take the easy way, live it up down, and be ashamed in the coming Kingdom.
In the same way, what is the picture that we are given of the high priest? How does Jesus currently fulfill that picture?
None come come to the Father but through the high priest. Now, we pray to the Father in the name of the Son.
So, let's look at a few things about the office of the high priest. This is taken from the New Topical Textbook for the sake of convenience and it is from Logos:
High Priest, The.
1. Specially called of God. Ex 28:1,2; Heb 5:4.
2. Consecrated to his office. Ex 40:13; Le 8:12.
3. Was called
a. The priest. Ex 29:30; Ne 7:65.
b. God’s high priest. Ac 23:4.
c. Ruler of the people. Ex 22:28; Ac 23:5.
4. The office of, hereditary. Ex 29:29.
5. Next in rank to the king. La 2:6.
6. Often exercised chief civil power. 1Sa 4:18.
7. Duties of
a. Offering gifts and sacrifices. Heb 5:1.
b. Lighting the sacred lamps. Ex 30:8; Nu 8:3.
c. Making atonement in the most holy place once a year. Le 16:1-34; Heb 9:7.
d. Bearing before the Lord the names of Israel for a memorial. Ex 28:12,29.
e. Enquiring of God by Urim and Thummim. 1Sa 23:9-12; 30:7,8.
f. Consecrating the Levites. Nu 9:11-21.
g. Appointing priests to offices. 1Sa 2:36.
h. Taking charge of money collected in the sacred treasury. 2Ki 12:10; 22:4.
i. Presiding in the superior court. Mt 26:3,57-62; Ac 5:21-28; 23:1-5.
j. Taking the census of the people. Nu 1:3.
k. Blessing the people. Le 9:22,23.
8. Sometimes enabled to prophesy. Joh 11:49-52.
9. Assisted by a deputy. 2Sa 15:24; Lu 3:2.
10. The deputy of
a. Called the second priest. 2Ki 25:18.
b. Had oversight of the tabernacle. Nu 4:16.
c. Had oversight of the Levites. Nu 3:32.
11. To marry a virgin of Aaron’s family. Le 21:13,14.
12. Forbidden to mourn for any. Le 21:1-12.
13. To be tender and compassionate. Heb 5:2.
14. Needed to sacrifice for himself. Heb 5:1-3.
15. Special garments of
a. Ephod with its curious girdle. Ex 28:6,7.
b. Girdle. Ex 28:4,39.
c. Broidered coat. Ex 28:4,39.
d. Robe of the ephod. Ex 28:31-35.
e. Breastplate. Ex 28:15-29.
f. Linen mitre. Ex 28:4,39.
g. Plate or crown of gold, &c. Ex 28:36-38.
16. Made by divine wisdom given to Bezaleel, &c. Ex 28:3; 36:1; 39:1.
17. Were for beauty and ornament. Ex 28:2.
18. Worn at his consecration. Le 8:7,9.
a. Worn seven days after consecration. Ex 29:30.
b. Descended to his successors. Ex 29:29.
19. Wore the ordinary priest’s garments when making atonement in the holy place. Le 16:4.
20. Office of, promised to the posterity of Phinehas for his zeal. Nu 25:12,13.
21. Family of Eli degraded from office of, for bad conduct. 1Sa 2:27-36.
22. Sometimes deposed by the kings. 1Ki 2:27.
23. Office of, made annual by the Romans. Joh 11:49-51; Ac 4:6.
24. Typified Christ in
a. Being called of God. Heb 5:4,5.
b. His title. Heb 3:1.
c. His appointment. Isa 61:1; Joh 1:32-34.
d. Making atonement. Le 16:33; Heb 2:17.
e. Splendid dress. Ex 28:2; Joh 1:14.
f. Being liable to temptation. Heb 2:18.
g. Compassion and sympathy for the weak and ignorant. Heb 4:15; 5:1,2.
h. Marrying a virgin. Le 21:13,14; 2Co 11:2.
i. Holiness of office. Le 21:15; Heb 7:26.
j. Performing by himself all the services on day of atonement. Le 16:1-34; Heb 1:3.
k. Bearing the names of Israel upon his heart. Ex 28:29; Song 8:6.
l. Alone entering into most holy place. Heb 9:7,12,24; 4:14.
m. Interceding. Nu 16:43-48; Heb 7:25.
n. Blessing. Le 9:22,23; Ac 3:26.
25. Inferior to Christ in
a. Needing to make atonement for his own sins. Heb 5:2,3; 7:26-28; 9:7.
b. Being of the order of Aaron. Heb 6:20; 7:11-17; 8:4,5,1,2,6.
c. Being made without an oath. Heb 7:20-22.
d. Not being able to continue. Heb 7:23,24.
e. Offering oftentimes the same sacrifices. Heb 9:25,26,28; 10:11,12,14.
f. Entering into holiest every year. Heb 9:7,12,25.
http://www.baptistboard.com/#_ftn1 http://www.baptistboard.com/#_ftnref1Torrey, R.A.:
The New Topical Text Book : A Scriptural Text Book for the Use of Ministers, Teachers, and All Christian Workers. Oak Harbor, WA : Logos research Systems, Inc., 1995, c1897