Not a Christian either, but...
Jesus teaches that earthly life is without value:
Life is spiritual. The body is of no value. (John 6:63)
I tell you, do not worry about your life. (Matthew 6:25)
Anyone who loves their life will lose it, while anyone who hates their life in this world will keep it for eternal life. (John 12:25)
Earthly life is intrinsically evil (Mark 7:21-22 & 10:18). Existence and the world are used as synonym for and are ruled by evil:
The world hates me because I testify that its works are evil. (John 7:7)
Now is the judgment of this world. Now the ruler of this world will be cast out. (John 12:31)
In Jesus's time, contraceptives didn't exist, so how could they encourage people to abstain from procreation?
Not everyone can accept this word, but only those to whom it has been given. For there are eunuchs who were born that way, and there are eunuchs who have been made eunuchs by others—and there are those who choose to live like eunuchs for the sake of the kingdom of heaven. The one who can accept this should accept it. (Matthew 19:11-12)
And Jesus said to them, The sons of this world marry, and are given in marriage: but they that are accounted worthy to attain to that world, and the resurrection from the dead, neither marry, nor are given in marriage: for neither can they die any more: for they are equal to the angels; and are sons of God, being sons of the resurrection. (Luke 20:34-36)
These are the ones who have not been defiled with women, for they are virgins. They follow the Lamb wherever He goes. They have been redeemed from among men as firstfruits to God and to the Lamb. (Revelation 14:4)
Now for the matters you wrote about: It is good to abstain from sexual relations. (1 Corinthians 7:1)
An unmarried man is concerned about the Lord’s affairs—how he can please the Lord. But a married man is concerned about the affairs of this world. (1 Corinthians 7:32-33)
Because in evil I was formed in the womb and in sin my mother conceived me. (Psalm 51:5)
And one from the Gnostic Christians:
For the defilement of the Law (the law of nature) is manifest; but undefilement belongs to the light. The Law commands (one) to take a husband (or) to take a wife, and to beget, to multiply like the sand of the sea...And they show that they are assisting the world; and they turn away from the light. (Testimony of Truth, from The Nag Hammadi Library of the Gnostic Christians)