1 Jesus said "before Abraham was I am" fully knowing that when Moses asked God what his name is God replied "I am who I am" thus openly declaring he is God.
2 Many times in John Jesus allowed people to fall on their knees and worship him. The first commandment states only God is to be worshipped . Therefore Jesus is God or he is guilty of a great sin which under the law of Moses is punishable by death and clearly cannot be a great prophet.
3 Jesus forgave sins. Only God can forget sins.
4 John 6:62 "What if you see the Son of man ascend where he was before"
While it is true that Jesus of Nazareth never said, "I am God," or "Worship me," he did make claims about himself which Jewish officials understood to be clear claims of divinity (Mark 2:3-7, John 6:41-42, 10:30-33, 5:18, 8:58-59, 19:7), which is why they had him executed. Jesus claimed that
--he came down from heaven (Jn 3:13, 6:38,42,62)
--and was sent by God (Jn 5:36-40, 10:36, 13:3, 16:28)
--to die as a ransom for the sins of many (Mt 20:28, 26:28; Jn 10:11),
--with power to forgive sin (Mt 9:2-6),
--to conquer Satan (Jn 12:31; Lk 10:18; Mk 1:23-26, 5:6-13),
--to speak for God (Jn 7:16, 8:25-28, 12:44-45,49-50, 14:10; Lk 9:35, 10:16),
--and to judge all mankind (Jn 5:22,27, 8:26, 12:48; Mt 25:31-33),
--as the exclusive way to God (Jn 14:6),
--the source of life (Jn 5:25-26, 6:40),
--the source of truth (Jn 14:6),
--the decisive factor in the eternal destiny of every man (Jn 3:18-19,36, 5 :24, 6:40, 8:24-25),
--possessing all authority (power) in heaven and earth (Mt 26:64, 28:18; Lk 10:22; Jn 13:3,13),
--
equal with God (Jn 5:18, 8:19, 12:44-45, 14:7-9, 16:15, 17:10); i.e. doing what God does (Jn 5:19):
----as the Father works, so the Son works (miracles) - (Jn 5:17),
----as the Father gives life, so the Son gives life (Jn 5:21),
----as the Father is Judge, so the Son is Judge (Jn 5:22),
----as the Father is to be honored, so the Son is to be honored (Jn 5:23),
----as the Father has life in himself, so the Son has life in himself (Jn 5:26),
----as the Father sends with authority and
power, so the Son sends with authority and
power (Jn 20:21),
----as the Father confers the kingdom, so the Son confers the kingdom (Lk 22:29),
----as the Father gives law, so the Son gives law (Mt 5:23-47, 12:7-8, 19:9, 21:23-27, chp 23),
--empowering the apostles to speak for him, as well as for God (Lk 10:16; Jn 13:20),
--empowering the apostles to recall and understand all things correctly (Jn 14:26, 16:13-15; Lk 24:48-49),
--and, in making these claims about himself, speaking exactly what the Father told him to say (Jn 12:49).
In these staggering claims, Jesus is saying that he is no less than God.
The Jewish officials knew exactly what Jesus was saying, accused him of blasphemy, and had him executed.