Question no.2 ans.
John encourages children, the new belivers by assuring that all their sins committed before salvation are forgiven, washed away by the precious blood of Christ, ie they are pure in heart. They are a new creation.
The next step, the young in Christ, they must keep on fighting the sins, the evil oneof this world and conquer it.
These young believers are strong in Christ as they feed on the word daily ,His word LOGOS stay in them, so they cannot be easily shaken by satan.
They have Holy Spirit to lead them to all righteousness od the Lord.
Fathers ,the mature christians or leaders,can be an example and a help to the child believer and the mature believer