The Eternal God saved me when I was 11 years old. I was in my bedroom by myself, upset about something. I thought to myself: pray about it. I got on my knees to pray and for the first time ever the realisation came upon me that I had personally sinned against God - that He is altogether Holy and I am not - and so for the first time in my life I realised I was separated from Him because of my sin.
I thought: how could He possibly forgive me for the things I had done (when you have a realisation of the holiness of God you understand the exceeding sinfulness of sin, understanding how sinful, for example, the lies of an 11 year old child are in the sight of God), and I had a pervasive sense of my guilt before Him. But immediately the image of a spotless lamb came into my mind and I was reminded of how Jesus Christ, the Son of God, was sinless, and how His death on the cross was sufficient to pay for my sin, as my Substitute.
Another doubt immediately followed: if I pray will He even hear me, and straightaway a verse from the Bible came into my mind: Romans 10:13 'For whosoever shall call upon the name of the Lord shall be saved'. I knew God IS Truth and cannot lie, and therefore if He makes such a promise He has to keep it. I prayed - believing in Christ's atonement made on my behalf, and repenting of sin and going my own way, not God's. And that was it: right then and there in a moment I was supernaturally born again of the Spirit of God without even fully realising, as an eleven year old, the full extent of what had happened.
He does not change. He is gracious. But He will judge sin. Come to Him. Today is a time when people have the opportunity to come, but that opportunity will not always be.
Spiritual experiences? God is so real that I would be lying if I were to write 'I believe' rather than 'I know'. It starts with belief, but then God proves Himself, not only of His being but then further: of His goodness, of His loving kindness, of His Word (the Bible), of His mercy, of His provision, of His continual care, of His patience, of His Omnipresence/Omniscience, etc.
If you want to know more read the Bible. I recommend starting in the Gospel of John, and reading the "Romans Road" Bible verses.
'ye shall seek me, and find me, when ye shall search for me with all your heart' Jeremiah 29:13