Saving faith only comes from God, and is not generated of ourselves. That faith comes by the working of the Holy Ghost in lost hearts, to grant us faith. Without that Spirit, we are all but carnal, natural, and in the flesh. Paul taught in Romans 8, that any such lost person cannot obey God or please Him at all. To receive the Gospel is to obey and please God, and therefore, such lost persons cannot receive the Gospel, or believe on Jesus Christ as their sacrifice for sin. But to be spiritually minded is to possess the Holy Ghost indwelling us. Everyone who is believing on Christ has the Holy Ghost residing inside him, and believes Christ's Gospel unto salvation. In 1 Corinthians 2, Paul makes this even more explicit: the things that God has prepared for His loved ones can only be known by His Spirit. These things include Gospel truth, our sanctification, and our glorification unto everlasting life through Jesus Christ! The natural man, being without the Holy Ghost, cannot believe any of these things! He can know them in a mechanical way, but he cannot lay hold on them, embrace them, trust in them, and receive them. All these things God reveals exclusively by His Spirit in our hearts. This is because only the Holy Ghost can know the mind of God, being in fact God. And all these things can only be conveyed by that Spirit of God Who declared them and worked them for the good of His elect people. Thus the saints are knit together with God by that Spirit of God indwelling us. He conveys these truths to us, His Spirit to our spirit. Thus we have the most intimate communion possible between God and man, a spiritual union only the saints possess.