Eph 2:8-10 - For by grace are you saved through faith (Jesus's faith, not mankind) and that not of yourselves. It is the gift of God. Not of works, lest any man should boast. For we are his workmanship, created (quickened to spiritual life) unto good works, which God hath before ordained that we should walk in them.
Most of the born again people do not accept that God's quickening grace is sovereign, without any action from mankind. Believing in spiritual things is a work along with accepting Jesus as your saviour, doing good works, repenting, confessing, etc.
Can you understand that these works of mankind to gain eternal salvation tend to take away part of God's glory and applying it to mankind? When God quickens a person to the new spiritual life, it drastically changes the person's life.
There are far more people that will inherit heaven than those that will not. The harmonized scriptures will show that.