Thought it was ...believe and thou shalt be saved.....
With a centurion’s faith.
Jesus also said:
15“Beware of the false prophets, who come to you in sheep’s clothing, but inwardly are ravenous wolves.16“You will know them by their fruits. Grapes are not gathered from thorn bushes nor figs from thistles, are they?17“So every good tree bears good fruit, but the bad tree bears bad fruit.18“A good tree cannot produce bad fruit, nor can a bad tree produce good fruit.19“Every tree that does not bear good fruit is cut down and thrown into the fire.20“So then, you will know them by their fruits.21“Not everyone who says to Me, ‘Lord, Lord,’ will enter the kingdom of heaven, but he who does the will of My Father who is in heaven will enter.22“Many will say to Me on that day, ‘Lord, Lord, did we not prophesy in Your name, and in Your name cast out demons, and in Your name perform many miracles?’23“And then I will declare to them, ‘I never knew you; DEPART FROM ME, YOU WHO PRACTICE LAWLESSNESS.’
I was saved in 1981 and "checked up on my salvation" maybe a hundred times in the early years.
Even today, Satan is capable of dangling doubt in front of my face, but the directive to "Hide Thy (God) word in my heart .. " is the solution to doubt.
Jesus used scripture to confront and defeat Satan in the wilderness temptation.
Salvation IS easy ... whosoever shall call upon the name of the Lord Shall ... Be ... Saved.