It is only available to those who, by God's grace, believe on the Lord Jesus Christ. You say that faith is the key that opens that unmerited favour, but how does a sinner "dead in trespasses and sins" as Paul puts in in Ephesians 2 manage to have faith?
God graces every accountable sinner with faith/MFW, but only those who exercise their faith by choosing to repent of ignoring God's Word and to love Jesus as Messiah/Lord until death satisfy God's requirement/condition/IF for salvation (GRFS).
My Scriptural support is this:
The normative way of stating the kerygma/GRFS in the NT is “Accept Christ Jesus as Lord” (as in
Acts 16:31,
2Cor. 4:5 &
Col. 2:6) or “Love Jesus as Messiah and Lord” (
John 8:42). The main points of Christian orthodoxy implicit in these statements can be explained or elaborated as follows:
1. There is a/one all-loving and just Lord or God (
Deut. 6:4,
John 3:16,
2Thes. 1:6), who is both able (
2Tim. 1:12) and willing (
1Tim. 2:3-4,
Ezek. 33:11) to provide all morally accountable human beings salvation or heaven—a wonderful life full of love, joy and peace forever.
2. Human beings are selfish or sinful (
Rom. 3:23,
2Tim. 3:2-4,
Col. 3:5), miserable (
Gal. 5:19-21), and hopeless (
Eph. 2:12) or hell-bound at the judgment (
Matt. 23:33 &
25:46) when they reject God’s salvation (
John 3:18,
Rom. 2:5-11).
3. Jesus is God’s Messiah/Christ and incarnate Son, the way that God has chosen (
John 3:16,
Acts 16:30-31,
Phil. 2:9-11) of providing salvation by means of his atoning death on the cross for the payment of the penalty for the sins of humanity (
Rom. 3:22-25 &
5:9-11), followed by his resurrection to reign in heaven (
1Cor. 15:14-28).
4. Thus, every person who hears the NT Gospel needs to repent and accept God’s justification in Jesus as Christ/Messiah the Lord or Supreme Commander (
Luke 2:11,
John 14:6,
Acts 16:31), which means trying to obey (
Phil. 3:12,
1John 1:8) His commandment to love one another (
Matt. 22:37-40,
John 13:35,
Rom. 13:9)—forever (
Matt. 10:22,
Psa. 113:2).
5. Then God’s Holy Spirit will establish a saving relationship with those who freely accept Him (
Rev. 3:20) that will eventually achieve heaven when by means of persevering in learning Truth/God’s Word/sanctification everyone cooperates fully with His will (
John 14:6,
17&
26,
Rom. 8:6-17,
Gal. 6:7-9,
Eph. 1:13-14,
Heb. 10:36,
12:1,
Jam. 1:2-4).
Such cooperation can be termed “the surrendered life”.
6. This creed summarizes revelation of the NT Gospel/Truth (
Matt. 26:13,
John 14:6), which fulfilled the OT revelation (
Matt. 5:17,
John 19:30,
Heb. 7:11-10:10) and culminates the search for salvation by souls who know only general revelation (
Rom. 1:20,
2:14-16,
Matt. 7:12). Seeking begins when souls love truth/repent of false beliefs (
2Thes. 2:10&
13,
Matt. 4:17,
7:7), which is the Way to eternal life God wills, who is the Lord Jesus (
Matt. 7:14,
John 1:14,
4:24,
14:6). Lacking this love leads to believing lies and debauchery (
Matt. 7:6,
Rom. 1:18&
25-26,
2Thes. 2:11-12).
How does your view differ and what is the Scriptural support for that?