Work Out Your Own Salvation

Therefore, my beloved, as you have always obeyed, so now, not only as in my presence but much more in my absence, work out your own salvation with fear and trembling, for it is God who works in you, both to will and to work for his good pleasure. | (Philippians 2:12-13 ESV)

First, the following are evidences that neither prove nor disprove one’s faith:

1. Visible morality (Matt. 19:16-21; 23:27).
2. Intellectual knowledge (Rom. 1:21; 2:17ff).
3. Religious involvement (Matt. 25:1-10).
4. Active Ministry (Matt. 7:21-24).
5. Conviction of sin (Acts 24:25).
6. Assurance (Matt. 23).
7. Time of Decision (Luke 8:13-14)

Now, here are some proofs of authentic faith:

1. Love for God (Ps. 42:1ff; Luke 10:27; Rom. 8:7).
2. Repentance from sin (Ps. 32:5; Prov. 28:13; Rom. 7:14ff, 2 Cor. 7:10; 1 John 1:8-10).
3. Genuine Humility (Ps. 51:17; Matt. 5:1-12; James 4:6, 9ff).
4. Devotion to God's glory (Ps. 105:3; 115:1; Is. 43:7, 48:10ff; Jer. 9:23-24; 1 Cor. 10:31).
5. Continual prayer (Luke 18:1; Eph. 6:18ff; Phil. 4:6ff; 1 Tim. 2:1-4; James 5:16-18).
6. Selfless love (1 John 2:9ff, 3:14; 4:7ff; John 13:34-35; 1 Pet. 1:22).
7. Separation from the world (1 Cor. 2:12; James 4:4ff; 1 John 2:15-17, 5:5).
8. Spiritual growth (Luke 8:15; John 15:1-6; Eph. 4:12-16).
9. Obedient living (Matt. 7:21; John 15:14ff, Rom. 16:26; 1 Pet. 1:2,22; 1 John 2:3-5).

If the first list is true of a person and the second list is false, there is cause to question the validity of a profession of faith. Yet if the second list is true, then the first list will be also. 

John MacArthur

Source: John MacArthur Study Bible