If externally focused religious leaders didn't like Jesus claiming in His day God as His Father, how much less will they like Christ-followers today claiming God (through faith in Jesus Christ) as their Father.
Every child of God should deliberately, actively, and (at least) annually from the heart and mind remember and celebrate for a few days his or her salvation by God through Jesus Christ.
A follower of Christ should never take lightly or despise his (her) birthright IN CHRIST - the grace of salvation comes with responsibility to surrender to God in faith day by day.