Man cannot "decide to trust in Jesus" when he is spiritually dead, 1 Cor 2:14. A man is not spiritually alive until he has been regenerated, Eph 2, and has been given the indwelling of the Holy Spirit.
it is the Spirit who testifies, because the Spirit is the truth. 7For there are three that testify: 8the a Spirit, the water and the blood; and the three are in agreement. 9We accept human testimony, but God’s testimony is greater because it is the testimony of God, which he has given about his Son. 10Whoever believes in the Son of God accepts this testimony. Whoever does not believe God has made him out to be a liar, because they have not believed the testimony God has given about his Son. - 1 John 5:6-10
Some reject the evidence of things unseen given to them by the Holy Spirit, and some accept that evidence and place their trust in it and are saved.