Let us look at this verse again:
"Very truly I tell you, whoever hears my word and believes him who sent me has eternal life and will not be judged but has crossed over from death to life" (Jn.5:24).
So do you agree with me that once a person believes then he is given eternal life?
These verses say nothing about how a person receives eternal life.
Simon is like the people who are spoken of here:
"Now when he was in Jerusalem at the passover, in the feast day, many believed in his name, when they saw the miracles which he did. But Jesus did not commit himself unto them, because he knew all men" (Jn.2:23-24).
Their faith was not a saving faith because it was based on nothing more than the miracles which they saw. on the other hand, since the LORD knows the heart of men and therefore He knows those who have true faith. And those receive eternal life. And the lord Jesus said that those to whom he gives eternal life shall never perish.
And His statement is an "unconditional" one which means that no conditions are attached. He does not say that I give them eternal life and they shall never perish UNLESS they do this or not do that.