Were the words in 1 Cor 7:8-9 from God? It is unlikely, for nothing near we heard from the prophets and Jesus. More concisely to say, it should be Paul's perspective based on his spiritual enlightenment from God. However, a man's perspective has a limitation by the era he lived, and we should put a little more effort to think how it is applicable for today.
1 Cor 7:9 is one of this typical controversial statement. Let's review it again;
9 But if they cannot control themselves, they should marry, for it is better to marry than to burn with passion. (1 Cor 7:9 NIV)
It sounds like marriage is to resolve one issue, avoid improper sexual relationship or fornication. This doesn't seem to be the teaching from God. God sees marriage a sacred relationship. He uses marriage to represent His covenant with Israel. He emphasizes 'Love' in the marriage, in Greek, 'Love' is 'Agape'. So did Paul downgrade marriage to mainly sexual relationship?
It may be worth noting that in the scripture, it often disclose marriage is a rough relationship, as if Israel has a rough relationship with God. God sees a marriage is holy when there is sacrifice love and perseverance in keeping the marriage, keeping the covenant amongst them.
Paul could be plainly to make a statement in 1 Cor 7:9 to ask the believers avoid sin due to improper sex. It did not eliminate the need of love and perseverance in a marriage, for it is a sure thing to do as God's people. It can be see in his teaching in Ephesians
22 Wives, submit yourselves to your own husbands as you do to the Lord.
25 Husbands, love your wives, just as Christ loved the church and gave himself up for her (Ephesians 5:22 & 25 NIV)
Therefore we cannot draw any conclusion by looking at one statement alone. Sometimes, an idea is so much complicated that it requires to read all related statements to get the real picture.