John 5:19

5:19 So Jesus answered them, “I tell you the solemn truth, the Son can do nothing on his own initiative, but only what he sees the Father doing. For whatever the Father does, the Son does likewise.

John 5:24-25

5:24 “I tell you the solemn truth, the one who hears my message and believes the one who sent me has eternal life and will not be condemned, but has crossed over from death to life. 5:25 I tell you the solemn truth, a time is coming – and is now here – when the dead will hear the voice of the Son of God, and those who hear will live.

John 6:26

6:26 Jesus replied, “I tell you the solemn truth, you are looking for me not because you saw miraculous signs, but because you ate all the loaves of bread you wanted.

John 6:32

6:32 Then Jesus told them, “I tell you the solemn truth, it is not Moses who has given you the bread from heaven, but my Father is giving you the true bread from heaven.

John 6:53

6:53 Jesus said to them, “I tell you the solemn truth, unless you eat the flesh of the Son of Man and drink his blood, you have no life in yourselves.

John 10:1

Jesus as the Good Shepherd

10:1 “I tell you the solemn truth, the one who does not enter the sheepfold by the door, but climbs in some other way, is a thief and a robber.

John 12:24

12:24 I tell you the solemn truth, unless a kernel of wheat falls into the ground and dies, it remains by itself alone. But if it dies, it produces much grain.

John 13:16

13:16 I tell you the solemn truth, the slave is not greater than his master, nor is the one who is sent as a messenger greater than the one who sent him.

John 14:12

14:12 I tell you the solemn truth, the person who believes in me will perform the miraculous deeds that I am doing, and will perform greater deeds than these, because I am going to the Father.